MEXICO CITY, Mexico (AP) _ Mexico City's archbishop on Sunday condemned last week's attack on a Roman Catholic bishop, whose car was sprayed with bullets as he returned from a visit in the mountains of southern Mexico.

Neither Bishop Arturo Lona Reyes nor the two passengers accompanying him were injured in the ambush by two masked gunmen, who shattered the car's windshield.

But Thursday's attack could still damage relations between the government and the church, which is preparing to mediate a new round of talks between the government and indigenous Zapatista rebels in the southern state of Chiapas.

``I hope these violent events, the struggle among parties, and these assassination attempts do not affect the peace dialogue, which should be preserved above everything else,'' Archbishop Guillermo Schulenburg said Sunday. .

The government has accused the church of siding with the poor Indians who rebelled 18 months ago. On June 23, it deported one American and two other foreign priests accused of organizing peasants to support the Zapatista rebellion.

In the Chiapas town of Yajalon, 3,500 Catholic peasants marched Sunday in support of the three deported priests.

``Why were they carried off? For preaching the word of God,'' vicar general Felipe Toussaint of the San Cristobal de las Casas Diocese said during an open-air Mass next to the 19th-century stone church.

``This is an attempt against the word of God. ... We are all in danger,'' Toussaint said, as women in embroidered dresses held umbrellas and lace shawls against the blazing sun.

Over the weekend, Oaxaca state Attorney General Hector Anuar Mafud opened an investigation into the attack on Reyes, known for his work with impoverished Indian communities. He also said the state government offered to protect the bishop while he carries out his priestly duties.

Bartoleme Carrasco Briseno, the former bishop of Oaxaca, suggested that the region's large landholders _ angered over the church's efforts to support Indian workers _ were behind the attack. He added that he had little hope the criminals would be caught.

``It's no longer worth calling for an investigation to get to the bottom of this _ no matter who's responsible,''' he said. ``That phrase no longer makes sense when the government's inability to govern is palpable.''

Bishop Ricardo Ramirez, of the Las Cruces Diocese in New Mexico, said the U.S. Catholic Conference is looking into the deportation of American priest Loren Riebe, who served in Yajalon for 19 years.

Ramirez plans to meet with U.S. Embassy officials in Mexico City on Tuesday.