PESHAWAR/KABUL – Pakistani forces have captured a stronghold of al-Qaeda-backed insurgents near the Afghan border after days of clashes in which 60 insurgents were killed, the military said on Sunday. Pakistani security forces mounted a major offensive in the ethnic Pashtun Bajaur tribal region in 2008 and declared it largely cleared after months of clashes. But militants, joined by comrades infiltrating from Afghanistan, staged a comeback in the region in recent weeks. Fourteen people were killed in a suicide bombing at a security checkpost in Bajaur late last month. Backed by fighter jets and helicopter gunships, Pakistani security forces helped by members of a militia from the area launched a new push to clear parts of Bajaur on January 27. The military has said it is now in control of the strategic Damadola area, about 12km (7 miles) north of Bajaur's main town of Khar. Damadola is an important insurgent stronghold and was the first Pakistani area to be attacked by US drones. Meanwhile, US forces detained a senior police officer in northeastern Afghanistan for alleged corruption and links to insurgents, an Afghan official and NATO said on Sunday. A senior provincial official said Atahullah Wahaab, deputy police chief in Kapisa province, was taken into custody by US forces on Friday. “The police commander was arrested by Afghan National Security Forces (ANSF) and coalition forces for illegal activity and corruption,” the US military, operating under NATO's International Security Assistance Force (ISAF), said in a statement. The statement said Wahaab was a "facilitator" of improvised explosive devices (IED), and was involved in the storage, distribution and installation of IEDs on roads in Kapisa. "He is also involved in bribery and corruption related to road refurbishment," the statement said, adding: "He has been clearly linked to criminal activities including a murder during the summer of 2009." Afghan security forces were involved in the operation that led to Wahaab's detention, it said. Abdul Aleem Ayar, a spokesman for the provincial government, said Wahaab was picked up by US forces at his home in Mahmoud Raqi, Kapisa's capital. In another development, a massive bomb destroyed a police vehicle in the Afghan city of Kandahar on Sunday, killing four officers and injuring two civilians, police said. The "very big bomb" was placed under a bridge and exploded as the police vehicle was passing, police colonel Abdul Ahmad told reporters. "Four policemen who were bringing food to their post were killed," he said at the site of the blast close to the city centre. A reporter saw a mangled police jeep and human flesh spread over a wide area. Remote-controlled bombs �" referred to by military authorities as improvised explosive devices, or IEDs �" are the key Taliban weapon in their fight against the Afghan authorities, which are supported by more than 100,000 foreign troops. Kandahar city is the capital of southern Afghanistan's Kandahar province, which along with neighbouring Helmand is the centre of the insurgency.