Mexico's immigration authority said Thursday it might expel 134 Italians on a human rights mission to Chiapas state for venturing beyond areas deemed acceptable by the government.

National Immigration Institute director Alejandro Carrillo Castro said his office would summon the Italians to meet authorities after they defied government orders late Wednesday by entering a renegade township that supports Zapatista rebels.The Italians, including four members of parliament, are the latest in a stream of international guests to tour the poor, violence-ridden southernmost state of Chiapas to observe human rights conditions.

At least 20 foreign observers have been expelled from Mexico so far this year after the government charged they committed similar visa violations in Chiapas.

"Nobody can believe they plan serious observation, holding hands and practically playing children's games," Carrillo said on Televisa network's Hoy Mismo newscast.

"This morning we ought to summon them into the offices of the immigration institute to analyze their immigration status . . . and determine what sanctions to hand out to those flagrantly violating the rules," Carrillo said.

The expulsions of foreigners have added to tensions in Chiapas that have been building since 45 Indian refugees were massacred by pro-government paramilitary gun-men Dec. 22.