Indian rebels have broken through an army cordon and established loose control over dozens of southern Chiapas state towns sympathetic to their cause.

At least 11 of those towns declared loyalty Monday to a rebel-supported "parallel government" set up by Amado Avendano Figueroa, a lawyer and newspaper publisher who the rebels say was cheated out of the governor's post in August elections.Hundreds of rebels of Maya Indian descent infiltrated a cordon of tens of thousands of army troops that had encircled so-called "rebel territory" since a cease-fire ending an Indian insurgency last January. The rebels had been believed trapped in their hideouts deep inside the Lacandon Jungle, a mountainous area bordering Guatemala.

Rebels and their sympathizers Monday blocked highways and roads with tree trunks, rocks and trash. Many of the main roads were cleared by the end of the day.

The military high command announced Tuesday that the thousands of troops in Chiapas will maintain their cease-fire as part of President Ernesto Zedillo's pursuit of a peaceful solution.

Armed rebels were reported to have infiltrated about 38 towns in Chiapas, Mexico's poorest state.

The rebel movement came almost a year after their uprising last New Year's Day, which they launched to demand better living conditions and unbiased courts. At least 145 people were killed in battles with government troops before a cease-fire was called Jan. 12.

Avendano, the candidate of the leftist Democratic Revolutionary Party, established a "transitional government" on Dec. 8, the same day the ruling party candidate, Eduardo Robledo Rincon, was sworn in as governor.

The rebels had insisted that Robledo's installation would mean the end of the cease-fire. They had demanded clean elections, democratic reforms and measures to give the state's impoverished Indian majority a better life.

"The majority of the country sympathizes with their just and valid demands," Avendano told a news conference Monday night.

The Institutional Revolutionary Party - or PRI - has ruled Mexico for 65 years. The party's critics say it has remained in power mostly through patronage, election fraud and strong-arm tactics.