PESHAWAR, Pakistan (AP) – A car bomb killed nine people close to the main northwestern city of Peshawar on Wednesday, the latest in a rash of attacks that are challenging recent police claims of progress against Islamist militants in the region.

Twenty others were wounded in the blast on a main road leading to Pakistan's border area with Afghanistan, said government official Siraj Ahmed Khan. Three children were among the dead.

The possible target of the bombing was not immediately clear. It was the third major bombing in or near the city in the last week.

Government and security force targets in Peshawar have been often attacked by the Pakistani Taliban, who have bases close to the frontier with Afghanistan. Pakistani security forces have traditionally had very little presence or authority in the tribally ruled region.

In December, city police chief Liaqat Ali pointed to a drop in attacks in 2010 as evidence authorities had ``broken the back'' of the insurgency in the city. He said the improvement was because of offensive police and army actions close to the border area and more police patrols and checkpoints in the city.

Also in the northwest, a group of militants on Wednesday attacked a security post in the Anarggi area of Mohmand tribal region, killing three paramilitary soldiers and wounding four. The troops returned fire and killed 16 insurgents, said Javed Khan, a government administrator.  

Like other tribal regions, Mohmand has seen anti-militant offensives by the Pakistani army over the past three years, but the militants have proven a tough enemy.