By Mubasher Bukhari

LAHORE, Pakistan (Reuters) - A Pakistani express train crashed into a freight train on Thursday killing at least four people and injuring 93, an emergency rescue service said.

The Awam Express bound for the southern city of Karachi hit the freight train about 25 km (15 miles) from the city of Multan, in Punjab province, trapping some passengers in overturned carriages.

"The last trapped victim has been extricated after four hours by cutting thick metal sheets of train cartridge with the help of hydraulic cutters," a provincial emergency service, Rescue 1122, said in report.

It said four people had been killed. Earlier, media put the death toll at six with more than 150 injured.

Pakistan's colonial-era railway network has fallen into disrepair in recent decades due to chronic under-investment and poor maintenance.

About 130 people were killed in July 2005 when a train rammed into another at a station in Sindh province, and a third train hit the wreckage.

(Writing by Drazen Jorgic; Editing by Nick Macfie, Robert Birsel)