LOGAR, Afghanistan, (Reuters/AFP) - Taliban gunmen and suicide bombers killed five police in an attack on Afghan government buildings south of the capital on Monday, officials and residents said, the latest in a series of brazen assaults in a growing insurgency. With violence surging across Afghanistan ahead of an Aug 20 presidential poll, Taliban spokesman Zabihullah Mujahid said six fighters wearing vests packed with explosives had attacked key buildings in Pule Alam, the provincial capital of Logar and an hours drive south of Kabul. Their targets included the governors office, police and election offices, he told Reuters by telephone from an undisclosed location. Unofficial police reports in Pule Alam said at least three of the suicide bombers may have been killed and two detained. A battle was still raging late on Monday afternoon and residents said US Apache attack helicopters could be seen hovering and sporadic gunfire heard. Abdul Rahim, an aid worker in the provincial capital, said five police were killed and 26 people were wounded. He said at least three of the Taliban attackers were dressed in burqas. Captain Elizabeth Mathias, a media officer for US and NATO-led troops, said she understood there had been a vehicle-borne bomb attack on the governors office and another attack on police. Private Afghan television station Tolo, quoting an unidentified Logar official, said Afghan security forces had been locked in gun battles with insurgents for several hours. It said Taliban fighters fired six rockets at government buildings. Military helicopters flew overhead and one aircraft fired a rocket into a building under construction, where the assailants were believed holed up, as smoke was seen rising from the small town, an AFP journalist said. The attack began when militants fired four rockets into the compound of the Logar province government from a building 150 metres away, provincial government spokesman Mohammad Darwish told AFP by telephone. The rockets hit the building and partially damaged the building. The governor was having lunch and no one was killed or wounded, he said. A suicide bomber managed to blow himself up inside the governors compound but caused no casualties, killing only himself, Darwish said. Two rockets slammed into the provincial police headquarters, again causing no casualties. The attackers armed with rocket-propelled grenades and machine guns, were holed up in a multi-storey building, from where they exchanged fire with security forces, Darwish told AFP. The area is cordoned by security forces and there is no fighting at the moment, he said later. We dont know if there are any other suicide attackers in the area at this stage. Interior ministry spokesman Zemarai Bashary told AFP that one policeman was killed. Joint security forces have surrounded the attackers and soon they will be either arrested or killed, he said. The NATO-led force in Afghanistan confirmed it had dispatched troops. Workers were trapped inside their offices and shopkeepers fled when the firing started, said a witness, local journalist Mohammad Obaid. The militants appeared to have taken control of a seven-storey building from where they opened fire, he told AFP, adding that a prison, elections office and counter-terrorism bureau were in the same area. A spokesman for the Taliban, Zabihullah Mujahed, claimed that six suicide attackers had entered the building and 21 people had been killed. Mondays attack resembled similarly brazen assaults on the eastern cities of Khost and Gardez last month, when gunmen and suicide bombers, some disguised as women, attacked government buildings. Attacks across Afghanistan have escalated since US Marines and British soldiers launched offensives in the southern province of Helmand, long a Taliban stronghold, in the past two months. The Taliban have vowed to disrupt the election and have called on Afghans to boycott the vote. Meanwhile, rockets were launched against Spains military base in Herat, western Afghanistan, in an attack that caused no injuries, the Spanish defence ministry said Monday. The rockets were launched (late Sunday) from a location north of the base but did not affect Spanish military personnel or equipment, it said in a statement.