A conductor and three members of his crew were arrested after a collision between two trains that left 33 people injured, three of them seriously, Cuban authorities said.

A freight train headed west toward Pinar del Rio and an eastbound passenger train with 110 travelers aboard ran into each other Wednesday morning near the campus of Havana's Jose Antonio Echeverria University, the Transport Ministry said in a statement.

Investigators' preliminary finding blamed the accident on the freight train's failure to yield to the other train.

The freight train's conductor and three of his crew "are in custody and at the disposal of the judicial organs," the ministry said.

A commission of safety experts will conduct a more extensive probe to "clarify the causes and conditions" behind the collision and to consider whether civil and criminal charges should be filed, the Transport Ministry said.

Nineteen people died and 149 others were hurt last year in 106 separate accidents on Cuban railways, according to official reports acknowledging an increase in such incidents in recent years.

Most of last year's accidents involved trains' running over cattle or people or collisions with vehicles at level crossings.