KARACHI- Two people were killed and 10 injured early Wednesday when a bomb exploded on railway tracks in Jacobabad district of Sindh, police officials said.

The explosion, which caused two of the train's cars to derail, occurred in the town of Thul at around 2am, police official Murtaza Mirani told AFP.

Thul is some 500 kilometres north of Karachi, while the train was headed for the northwestern city of Peshawar. "Fortunately, the bogies did not overturn as the train was slow, thus averting a bigger catastrophe," Mirani said.

Ashraf Soomro, a local railway official, said that the injured had been taken to a hospital, while the other passengers were being looked after. "We are busy repairing the damaged tracks and will send the passengers to Peshawar as soon as possible," he said.

Mirani said so far no terrorist groups had claimed responsibility for the attack, adding: "We can't comment right now until our investigation is complete."

Terrorist attacks are less frequent in the south than in the country's restive northwestern border area with Afghanistan.