SAN SALVADOR, El Salvador (AP) _ Leftist rebels on Thursday shot down a Salvadoran government helicopter north of the capital, the army announced. Two of the three crewmen aboard were injured, the army said.

The attack near the town of Suchitoro, 25 miles north of San Salvador, came eight days after rebel gunfire downed a U.S. military helicopter.

The rebels have increased pressure on the Salvadoran air force in recent months and have brought down two government planes with surface-to-air missiles. Numerous helicopters have been shot down or damaged, usually by rifle fire.

Government air capacity has been an important factor in the 11-year-old war, which has claimed more than 73,000 lives.

The army communique said the two crewmen were injured when the Hughes-500 helicopter was downed Thursday while supporting ground troops near Suchitoro.

On Wednesday, the guerrillas conceded their forces may have executed two crew members of the American helicopter they shot down Jan. 2 over eastern El Salvador.

The rebel Farabundo Marti Liberation Front said two guerrillas have been arrested ''on suspicion of having assassinated wounded prisoners of war.''

U.S. Chief Warrant Officer Daniel S. Scott, 39, apparently was killed outright in the crash. Autopsy reports indicated Pfc. Earnest G. Dawson Jr., 20, and Lt. Col. David H. Pickett, 40, survived the impact but were later shot to death at close range.

The downing of the helicopter and charges the crew had been executed apparently played a role in President Bush's decision this week to ask Congress to restore $42.5 million in military assistance to El Salvador.

The money has been frozen because of what the administration said was a lack of progress in solving several human rights cases in El Salvador.

Other reasons for the restoration include contentions that the rebels continue to get arms from outside the country, especially sophisticated surface-to-air missiles.