Akhtar said medical staff had declared a state of emergency to cope with the victims.

Security officials said Tuesday's bomb was detonated by remote control.

"It was a remote control bomb and was planted in a bicycle," Riaz Khan, a provincial police spokesman, told the AFP news agency.

No responsibility claim

No group claimed responsibility for the attack, but a campaign of bombings in Pakistan has been blamed on the Pakistani Taliban and al-Qaeda-linked fighters who have killed 3,300 people since July 2007.

Dera Ismail Khan district borders the tribal district of South Waziristan, where Pakistan launched a major offensive against the homegrown Taliban last year.

Pakistan continues to battle anti-government fighters in much of the semi-autonomous tribal belt along the Afghan border, which the US calls a global headquarters of al-Qaeda.

Much of the fighting has been concentrated against the Tehreek-e-Taliban Pakistan (TTP), which the US says was behind a failed car bomb plot in New York.

The plot has been linked to Faisal Shahzad, a Pakistani-American, who allegedly left a car bomb in Times Square on May 1 and was arrested on board a plane bound for Dubai two days later.

The Dera Ismail Khan attack came a day after Pakistan's military said it had killed more than 60 suspected fighters close to the country's border with Afghanistan.

Fighter jets and ground forces attacked targets in Orakzai tribal region in the latest attempt to flush out Pakistani Taliban fighters from the area.

Up to 42 people died in Monday's air raids, with a further 18 killed by Pakistani troops in the ground.

One soldier died and 10 were wounded in the fighting, the military said.