A truck packed with Central American migrants swerved off a highway in southern Mexico late Thursday, leaving at least 25 dead and 29 injured, officials said.

The accident happened in Chiapas state which borders Guatemala, the state attorney general’s office said in a statement.

The three-ton truck ran off the road and overturned, it said. Every year thousands of Central Americans, mainly from Honduras, El Salvador and Guatemala, attempt dangerous trips through Mexico trying to reach the United States.

Many travel in group caravans for safety, while others hire people traffickers who put them in overcrowded trucks with appalling and sanitary conditions.

In October a caravan with as many as 7,000 people traveled through Mexico all the way to Tijuana on the border with California before eventually disbanding.