Salvador Rebels Kill Five Troops in Mortar Attack : Central America: The latest assault brings week’s toll to 89 in the year’s biggest military campaign.

Leftist rebels, continuing their biggest military campaign in a year, Thursday fired mortar shells at an army garrison in the town of San Miguel, killing at least five Salvadoran soldiers, the armed forces said.

The assault brought the death toll in the fighting since Monday to 89, including at least 38 soldiers, according to government figures. At least 300 people have been wounded, including 164 army troops, official figures show.

The guerrillas claimed Thursday they had killed or wounded 395 soldiers in combat since Monday night, when the rebel Farabundo Marti National Liberation Front launched its latest campaign.

The rebels have said the assaults are aimed at forcing concessions from the U.S.-backed government in deadlocked peace talks. In a statement Thursday, it accused the military of understating its losses.

In their assault on San Miguel, 85 miles east of the capital, the guerrillas killed five soldiers and wounded four when they rained mortar fire on the headquarters of the 3rd Military Brigade, military sources said.

Rebels early Thursday also struck in the capital, shelling a power plant and triggering power outages in San Salvador.

Government forces fired volleys of rockets from helicopters against suspected guerrilla positions on the slopes of San Salvador Volcano overlooking the capital. Rebels also attacked military positions in the central province of Cuscatlan and toppled power pylons near the town of Guazapa, 12 miles north of the capital.

In Washington, State Department spokesman Richard Boucher accused the rebels of upsetting negotiations with the government to end the 11-year-old civil war.

“The FMLN should end its hypocrisy and begin to negotiate seriously toward a cease-fire and final political settlement,” he said.

The peace talks are deadlocked over rebel demands for the reduction, purge and eventual disappearance of the military in return for their own demobilization.