MEXICO CITY (AP) _ Salvadoran rebel leaders say rightist politicians and hardliners in the military are pressuring President Jose Napoleon Duarte to reject the leftists' request for another round of peace talks.

''The process of dialogue is in serious danger of paralysis,'' said Ruben Zamora, vice president of the Democratic Revolutionary Front. The front is the political umbrella group allied with the guerrilla movement in El Salvador.

''We see the situation as very grave,'' Zamora added.

He and three other rebel leaders, meeting with reporters Tuesday, said they sent a proposal to Duarte on Jan. 11 requesting a third round of talks but have received no reply.

The proposal was sent through El Salvador's Roman Catholic Church, which has been trying to bring the two sides together to end the five-year civil war. The first peace talks were held in November with direct participation by Duarte and key rebel leaders. The second round, involving lower ranking officials from both sides, was held last month.

Salvadoran government and church leaders recently expressed doubt that any talks will be held before National Assembly elections are held March 17.

They blamed the breakdown in the talks on pressure on Duarte from the rightists who control the assembly.

The assembly has introduced a series of bills in the past two months that challenge Duarte's control of the government.

Zamora said military leaders told Duarte in December that they would not accept peace talks dealing with questions of rebel participation in the government or that would affect current anti-guerrilla operations.

''The (political) crisis of December has forced Duarte to face reality: That is, that he does not have power,'' Zamora said.

''We are afraid that after the elections, the balance of power will be even more unfavorable for Duarte,'' he added.

Duarte's centrist Christian Democratic Party, which controls 24 of the 60 assembly seats, is not expected to win a clear majority in the elections. Four conservative parties, which often act as a bloc, hold 34 seats, and the other two seats are held by a small swing party.

In San Salvador, leftist rebels said government forces had captured one of their commanders and another woman who was her companion and claimed the two were being tortured.

A report over the rebels' clandestine Radio Veneremos claimed the two women had been seized Dec. 30. It said the guerrillas would hold the military command responsible for their safety.

Col. Ricardo Cienfuegos, head of the armed forces press office, told The Associated Press he had no knowledge about the two woman being detained.

Radio Venceremos identified the women as Commander Janet Samour Hasbun, a 34-year-old member of the Central Committee of the People's Revolutionary Army, one of five rebel groups fighting the U.S.-backed government, and Maximina Reyes Villatorio, 26.

It said they were captured in San Miguel, 83 miles east of the capital, and turned over to the military high command in San Salvador on Jan. 2.

In Mexico City, Salvador Samayoa, a member of the rebels' political commission, told reporters the guerrillas had not announced the women's capture earlier because they were working through the Roman Catholic Church and human rights groups to get the army to admit it had them.

In another development, national police said guerrillas attacked a military base at Santa Rosa de Lima, 106 miles east of San Salvador, before dawn on Tuesday, killing a soldier and a civilian in a 15-minute battle.