Pakistani officials say a bomb targeting a police vehicle has killed at least 11 people in the volatile North West Frontier province.

The officials say militants set off the remote-controlled car bomb as the van reached a bridge Thursday near the town of Bannu.

At least nine police officers and two prisoners died in the attack.

Meanwhile, hundreds of lawyers dressed in black suits rallied in cities across Pakistan Thursday, bringing traffic to a halt.

Some shouted slogans against the government and Pakistan People's Party leader Asif Ali Zardari.

The lawyers blame Zardari for preventing the reinstatement of 60 judges deposed by former President Pervez Musharraf last November under emergency rule.  

The government restored eight of the judges, in the southern province of Sindh, Wednesday, but lawyers have criticized the move, saying it is not enough.

Pakistan's lawyers say the handful of re-instatements harms their demands for the restoration of all judges, including Supreme Court Chief Justice Iftikhar Mohammed Chaudhry.

Earlier this week, former Prime Minister Nawaz Sharif quit the coalition government over differences about the judges with Zardari and the PPP.  

Also Wednesday, officials said Pakistani forces killed 44 insurgents in the northwestern Bajaur region as part of an operation to rid the area of Taliban and al-Qaida-linked militants.

More than 500 militants and 22 soldiers have been killed in Bajaur, with thousands more people displaced since the offensive began.

Some information for this report was provided by AFP, AP and Reuters.