At least seven people died and 10 were wounded Monday when a bomb exploded that had been planted on the railroad tracks connecting the Pakistani cities of Rawalpindi and Quetta, police told Efe.

The attack, for which no group has claimed responsibility, occurred near the central town of Nasirabad and the bomb exploded as the train ran over it, a police official in nearby Dera Murad Jamali said.

Nonetheless, a source in the Nasirabad police had said soon after the explosion that the bomb was hidden under a seat in one of the passenger cars.

The Quetta-bound train derailed when the bomb went off and four train cars overturned.

The injured have been taken to a hospital in Dera Murad Jamali near Nasirabad in the conflicted province of Baluchistan, the base of many separatist armed groups.

Over the past year the region has been the scene of other such attacks, the latest being in August in the Bolan district near Nasirabad in which four people died.

In that incident, the attackers fired a rocket that stopped the train, and when security forces arrived, a shootout began.

Despite having inherited a good railway system from the days of British rule, Pakistan has ignored the train as a means of transport and today scarcely a score of trains run daily in the country, even though the government has plans to restore the railroads. EFE