KUNAR (Reuters/AFP) - Taliban insurgents overran a remote district in eastern Afghanistan after days of heavy fighting in the area, a provincial police official said on Saturday, while a suicide bomber blew himself up near a Nato base in Kabul. The insurgents hoisted their flag in the district centre, which they also seized briefly last year, after forcing police to retreat, Afghan provincial officials and the Taliban said. The battle started earlier this week in the Barg-i-Matal district of mountainous Nuristan province, a remote area bordering Pakistan, when hundreds of Taliban fighters stormed the area administrative headquarters, said Qasim Payman, police chief of the province. The fate of police officers guarding the administrative compound - which houses government, police and judicial offices - was unclear. The police force in the area has tactically retreated from the district after days of fighting, he told Reuters, adding there were no signs of reinforcements despite repeated requests. Jamaluddin Badar, provincial governor of Nuristan, said Afghan forces had retreated in order to prepare for a counter-attack. We have lost the district to the Taliban ... but will push them back soon, he said. Taliban spokesman Zabihullah Mujahid confirmed the group now controlled the district after days of heavy fighting. The Taliban flag is flying high in the district centre and it is a huge victory for our fighters, he told Reuters by cellphone from an undisclosed location. Our fighters are still clearing other villages and looking for Afghan police and their supporters. A Nato airstrike, meanwhile, killed a Taliban shadow governor and several of his associates in the relatively peaceful northern Baghlan province Friday night, the alliance said in a statement. Afghan security officials confirmed the incident and said several key Taliban commanders were among the dead. After a lull of almost three months in Kabul, attacks have escalated, with another on Saturday near a military caterer, when a suicide attacker with explosives strapped to his body blew himself up, causing no casualties. The explosion took place east of the capital, close to a warehouse and supermarket run by Supreme Food Services, supplier of food to the foreign military, Interior Ministry spokesman Zemarai Bashary told AFP. It was suicide attack and the suicide attacker detonated explosives strapped to his body, he said.