OKLAHOMA CITY (AP) _ One suspect was in jail and two witnesses were being questioned, but the second man wanted in the deadly bombing of the federal building was unidentified and still at large this morning, the FBI said.

Rescuers resumed searching the ruins late this morning after wind and rain had forced them to stop for more than two hours.

``We're starting to get into the day-care area. The firefighters are picking up toys and looking at them and handing them to each other,'' Assistant Fire Chief Jon Hansen said, holding a red plastic fire truck that was found in the wreckage as he talked to reporters.

No new bodies had been found since the search resumed, he said.

Timothy McVeigh, 26, was held in a correctional center after being charged Friday with the bombing. Authorities said McVeigh, an ex-soldier, was enraged at the government for the 1993 Waco, Texas, cult disaster.

A second man, Terry Nichols, 40, was being held in Kansas, where he lives, and Nichols' brother, James, was held overnight in Michigan. Both are considered material witnesses, Justice Department spokesman Carl Stern said in Washington.

``These are very encouraging and positive steps, but there is much work to be done,'' said Weldon Kennedy, special FBI agent in charge of the investigation. He said the search was underway at other locations around the country but would not elaborate.

FBI agents arrived Friday in Kingman, Ariz., where a mail drop was listed as McVeigh's address in court documents filed in Oklahoma. Sheriff's spokeswoman Tonya Dowe said a number of agents were in town but would not comment further.

In Washington, Stern said James Nichols was questioned and held Friday after his farm in Decker, Mich., was searched by investigators. Stern said both Nichols brothers were cooperating with federal investigators. Neither man has been charged.

Under federal law, prosecutors can obtain court permission to hold people as material witnesses in order to ensure that their testimony is available for investigators.

Virgil Strickler, sheriff of Sanilac County, Mich., said James Nichols was to be taken to Oklahoma soon for questioning.

The second suspect, as yet unidentified suspect, was the man whose composite sketch was released Thursday by the FBI, the one with a tattoo on his left arm, Kennedy said.

In Oklahoma City, the toll from the bombing remained at 78 dead. About 150 people were still unaccounted for, and 432 others were injured in the blast, caused by thousands of pounds of fuel-and-fertilizer explosives packed into a Ryder rental truck.

Those searching the rubble moved cautiously amid fears that cracks on the south side of the building could cause part of it to collapse as workers remove rubble, and that lightning could strike metal reinforcing rods exposed by the blast.

``We've got some cracks right now that are widening on us,'' Hansen said. He said officials were monitoring the cracks with time-lapse cameras, which can detect if they are widening.

Many spaces in the rubble have been spray-painted ``DB'' to identify where the bodies are.

``We see, we know where bodies are in the void but we can't get to them because of the rubble,'' Hansen said.

Ray Blakeney, director of operations for the state medical examiner's office, said 29 of the dead had been identified, including five of the 13 children's bodies that have been recovered so far.

Fire Chief Gary Marrs said four bodies had been located in a building across the street from the federal building. Some had not yet been removed, he said.

Rescuers were still hoping to find survivors, but ``certainly as time goes by, the chance decreases,'' Blakeney said.

A one-story brick building that had been weakened by Wednesday's blast at the federal building 2 1/2 blocks away collapsed this morning. Three people inside barely escaped injury.

One of the three, a man identified only as Don, told reporters that the structure's west wall had been leaning 6 to 8 inches at the top since the blast. The building housed a taxi dispatching service.

House Speaker Newt Gingrich spent more than an hour touring the bomb site early today, arriving about 4 a.m. Gingrich did not want to disrupt the rescue effort, so he consulted with Federal Emergency Management Agency director James Witt before choosing a time to tour the site.

``He spent a pretty substantial amount of time visiting with rescue workers, and he thanked them for their help,'' said Rep. Frank Lucas, R-Okla., who along with Rep. Ernest Istook, R-Okla., joined Gingrich on the tour. ``It obviously made an impression on him.''

``I appreciate the speaker for not turning it into some kind of show.''

Gingrich also met with FBI agents to discuss the continuing investigation.

After a 15-minute appearance before the magistrate he called ``sir,'' McVeigh was taken to the El Reno Federal Correctional Center 30 miles away pending court hearings next Thursday.

Two court-appointed attorneys represent him for now against a charge of ``malicious damaging and destroying by means of an explosive a building or real property, whole or in part, possessed or used in the United States.''

The government has said it would seek the death penalty.

Nichols, wearing blue jeans and accompanied by his wife and daughter, drove his blue pickup into the police parking lot and walked inside to surrender, saying he had heard his name on television, The Wichita Eagle reported today.

McVeigh, a ringer for an FBI artist's suspect's sketch in circulation since Thursday, had been sitting in a county jail 63 miles away since his arrest in a traffic stop less than 1 1/2 hours after the bombing.

Many in a crowd of 250 spectators booed and some shouted ``Baby-killer!'' as he was brought out of the Noble County Jail for the trip here. Dozens of base personnel and their families also yelled and booed from across the road when heavily armed federal agents and soldiers took him to the court appearance.

Stopped Wednesday morning because he didn't have a license plate on his 1977 Mercury Marquis, McVeigh also was charged with carrying a concealed weapon after the trooper took a loaded Glock semiautomatic from him, authorities said. But he likely would have posted bail on five misdemeanor counts and slipped away if he hadn't been recognized.

``He came desperately close to making bail,'' said Mark Gibson, assistant district attorney in Perry.

After early suspicions that the Alfred P. Murrah Federal Building was targeted by international terrorists, Friday's developments pointed strongly to homegrown violence from the extremist anti-government movement.

In court papers, the FBI said a former co-worker called the bureau Friday after seeing the sketch on television. He described McVeigh, who served in the Army at Fort Riley, Kan., as having ``extreme right-wing views'' and anger over Waco.

The Waco debacle began with a deadly gun battle between the Branch Davidian religious cult and agents of the Bureau of Alcohol, Tobacco and Firearms. After a 51-day standoff, FBI agents stormed the cult's fortress on April 19, 1993, and the compound went up in flames. Eighty-six people, including cult leader David Koresh, died in an inferno investigators believe was caused by the cultists.

Waco has become a rallying cry for right-wing, anti-government extremist groups, and ATF was among some 20 agencies that had offices at the bombed building.

Elsewhere Friday, neighbors of James Nichols said the brothers attended meetings of extremist antigovernment groups. McVeigh had used the Decker address when obtaining a Michigan driver's license and was described as a friend of James Nichols by an unnamed Nichols relative.

McVeigh's arrest and the questioning of the Nichols brothers came less than a day after the FBI flashed sketches of two unidentified suspects around the world and offered a $2 million reward for information leading to their capture.

The FBI said the two suspects were believed to have rented the truck used in the attack from a Junction City, Kan., body shop. The suspects had stayed at the Dreamland Motel there the four days before the bombing, witnesses told the FBI.

President Clinton, declaring Sunday a national day of mourning, said he and his wife, Hillary, would visit Oklahoma City then for a memorial service.