By Daina Beth Solomon and Raul Cortes
MEXICO CITY (Reuters) -Five people have been arrested for alleged roles in the deaths of 39 people after a fire at a Mexican migrant detention center this week, authorities said Thursday, as pressure mounts to understand why victims appeared to be left in their cells as the area filled with smoke.
As part of the homicide investigation, Sara Irene Herrerias, head of the attorney general office's human rights unit, said warrants had been issued for three officers at the government's National Institute for Migration (INM), two private security officers, and the person accused of starting the fire.
She did not clarify which of the six arrest orders remained pending.
A private company, Grupo de Seguridad Privada CAMSA SA de CV, was responsible for security at the center in the northern border city of Ciudad Juarez, said Security Minister Rosa Icela Rodriguez.
CAMSA did not immediately respond to a request for comment.
Several irregularities were found when investigators looked into CAMSA, Rodriguez said, adding the government has asked the migration institute to withdraw its contract with the company. She had said investigators were looking into how members of the private security company were trained.
Federal agents will take over security at migrant centers in the state of Chihuahua, where the center is located, Rodriguez said.
Rodriguez said there had been a failure of oversight by government officials in various areas, including those who approved contracts "without checking what they really consist of."
A complaint filed with federal prosecutors on Wednesday, seen by Reuters, alleges that the state's top migration official, Salvador Gonzalez, had been alerted to the fire and ordered the migrants not be released.
Jorge Vazquez, the lawyer who filed the complaint, told Reuters the information came from his clients who were familiar with what occurred. He declined to give the names of his clients, saying it would put them in danger.
Gonzalez told Reuters the allegations were untrue. He said he did not order the migrants remain locked up, and added that he does not communicate directly with the managers of detention centers.
A short video circulating on social media - appearing to be security footage from inside the center during the blaze - showed men kicking on the bars of a locked door as their cell filled with smoke.
Three uniformed people can be seen walking past without trying to open the door. Investigators have said the video is part of the probe.
Authorities have said they believe the fire, which killed male immigrants from El Salvador, Guatemala, Honduras, Venezuela and Colombia, was started by migrants setting mattresses on fire as a form of protest.
The fire is one of the deadliest migrant incidents in recent years.