QUETTA: Train servicebetween Quetta and the rest of the country could not be restored and may remain suspended for at least three more days after a bomb blast earlier this week severely damaged a railway track and a bridge, officials said on Thursday.

The powerful blast on Tuesday derailed the Quetta-bound Jaffar Express as it passed through the Spezent area of the Mastung district,injuring atleast12 people.

`Train service between Quettaand the rest of the country will remain suspended for another three days,` said Omran Hayat, divisional superintendent for Pakistan Railways in Quetta.

He said work on the damaged track and bridge is still underway and that service will be restored after security clearance is granted.

Six bogies of the passenger train, which was travelling from Peshawar, were derailed and one overturned in the explosion.

The injured, who included two police personnel, women and children, were taken to hospitals in Quetta.Railway officials said a small railway bridge and a large portion of the track were badly damaged.

The derailed bogies have since been removed, and repair work is in progress,they said.

An initial investigation by railway police and security forces revealed that 5 kilograms of explosives had been planted on the track and were detonated by remote control.

Meanwhile, Pakistan Railways has decided to tighten security along its tracks and said all possible steps would be taken to ensure the safety of passenger and goods trains.