Leftist guerrillas attacked two major army bases in eastern El Salvador, according to rebel and armed forces reports Tuesday.

The rebels said the attacks on the bases near San Miguel marked the beginning of a new offensive against the U.S.-backed government.The Marxist-led insurgents said on their clandestine Radio Venceremos they inflicted 28 casualties on government troops Monday night in an attack on the 3rd brigade headquarters in the provincial capital of San Miguel. The report did not distinguish between killed and wounded.

Lt. Salvador Gonzalez Quezada, spokesman for the 3rd brigade, said no government soldiers were killed or wounded in the attack. A civilian woman was wounded during fighting outside the brigade compound, he said.