Mexico's government is offering a reward of 30 million pesos (nearly $3 million) for information leading to those behind a casino attack in which more than 50 people died.
Several gunmen burst into the building in broad daylight, doused it with fuel and set it alight. The death toll is now thought to be 52.
Officials suspect organised crime was behind the attack, one of the deadliest since a 2006 crackdown on drug cartels.
The BBC reports the attack happened mid-afternoon when 100 staff and customers were inside the Casino Royale in the northern city of Monterrey.
One survivor said the gunmen threatened them and then sprayed some kind of fuel that they set alight.
"It was chaos inside," said one woman who got out. "You couldn't see and the smoke was choking us. Some people didn't reach the exit and fell just metres from the door."
Another person who escaped said there was complete panic.
The BBC's correspondent in Monterrey says the casino's emergency doors were locked and the place became a death trap.
President Felipe Calderon has declared three days of mourning for the victims of the fire.