VIEQUES, Puerto Rico (AP) _ Helicopters hovered overhead and U.S. warships loomed offshore Vieques Island amid reports that federal agents were planning to evict protesters from a contested U.S. Navy bombing range.

Tensions increased Monday with reports that the USS Nashville and USS Bataan picked up 1,000 Marines in North Carolina en route to Vieques. The Marines reportedly would secure the range's perimeter once protesters are removed.

``I'm not going to fight with them,'' said Luisa Guadalupe, 82, a protester helping to block the main entrance to the Vieques range. ``But to get me out of here they're going to have to arrest me.''

Navy exercises that had been held for 60 years on the island, just east of Puerto Rico, were suspended a year ago after stray bombs killed a civilian security guard, releasing pent-up resentment in the U.S. territory.

There are 50 protesters at several camps inside the range. They stand in the way of an agreement between the local government and President Clinton allowing the Navy to resume limited training until Vieques' 9,300 residents decide in a referendum whether the Navy should leave.

Arrests would be carried out by federal agents in an FBI-led operation, according to Pentagon officials.

On Monday, three U.S. warships appeared off Vieques' north coast, accompanied by two Coast Guard vessels. The hull number on one of them was 13, corresponding to that of the USS Nashville, an amphibious transport. The Bataan is an amphibious assault ship.

The warships later steamed off to nearby Roosevelt Roads Naval Station on the main island of Puerto Rico. An Army barge, meanwhile, delivered Puerto Rican riot police vans to Vieques.

Several Navy helicopters flew over the range.

Most protesters planned to surrender peacefully. But a few threatened to scatter into the bomb-littered bush, raising the specter of a dangerous hunt.

Protesters also say they will cut through fences and ride in by horseback to replace any demonstrators who are arrested.

Up to 150 people gathered outside the range's main gate late Monday. Some played dominoes or read books. Others posed for pictures in front of a giant sign reading ''378 days of peace taken back from the oppressor!'' A few jeered as a Humvee carrying five soldiers drove by.

Early today, organizers showed protesters where to find jars of petroleum jelly and goggles to use as protection against pepper spray. They also handed out small plastic bags, each with a rag soaked in a vinegar-water mixture to minimize the effects of any spray or tear gas.

Organizer Robert Rabin warned people to get rid of anything resembling a weapon _ even a pocketknife _ and he urged them not to fight authorities.

``We want to provoke arrests. We want to obligate them to arrest us,'' he told the protesters. ``But we are not going to be fighting with the police.''

Four observers from the government Civil Rights Commission arrived with fliers explaining protesters' rights if arrested.

At a Roman Catholic Mass, the Rev. Pedro Rafael Ortiz said the bombing has caused ecological damage and ``slow deaths,'' alluding to high cancer rates. ``God wants us to be in this struggle,'' he said. ``The Navy needs to repent for the evil it has done and not sin again.''

Local politicians arrived Monday to reinforce the gate camp and said arrests would anger Puerto Ricans in New York, Florida and Chicago _ much as the Justice Department raid to seize Elian Gonzalez from his relatives' home in Miami enraged the Cuban-American community there.

``This is going to be worse than Miami for the Clinton administration,'' said Jose Aponte, a prominent Puerto Rican Democrat and the mayor of Carolina, a San Juan suburb. ``Arrests are not going to end the fight. They are going to extend it to the rest of Puerto Rico and big cities in the United States.''