An outspoken priest who runs a shelter for migrants in southern Mexico has temporarily left his facility after receiving death threats, the shelter coordinator said Monday.

The "Hermanos en el Camino" shelter run by the Rev. Alejandro Solalinde said in a statement that the Roman Catholic priest is "protecting his physical safety" until state and federal prosecutors thoroughly investigate the threats.

The shelter said Solalinde is expected to return to his work, but didn't say when.

"International human rights organization that work closely with Solalinde suggested he go away for a while," said Jose Alberto Donis, who coordinates activities at the shelter.

Donis said the most recent threat came on April 15.

Prosecutors in southern Oaxaca state have said they are investigating and are providing police security for Solalinde.

Solalinde has become widely known in Mexico for publicly denouncing corruption and abuse of mainly Central American migrants who cross into Mexico seeking to reach the United States.

Last year, he took the unusual step of publicly implicating the violent Zetas drug cartel in the kidnapping of migrants. He also criticized corrupt police.

"His comments made candidates and organized crime gangs uncomfortable," Donis said.

Also Monday, a group of experts from the U.N. and the Inter-American Commission on Human Rights called on Mexico to approve a proposed law to defend human rights advocates.

Margaret Sekaggya, the United Nations special investigator for the treatment of human rights defenders, said such activists in Mexico "desperately need the state's effective protection now. "

"They continue to suffer killings, attacks, harassment, threats, stigmatization and other serious human rights violations," she said.