Suicide bombers and gunmen targeted Afghan government offices Saturday, sparking gun battles with security forces and causing casualties in the third Taliban commando raid in days, officials said. Three assailants strapped with explosives blew themselves up near offices and a bank in the eastern town of Khost while others armed with machine guns and rockets fought security forces, said a defence ministry spokesman. 'A group of terrorists attacked government buildings and a commercial bank. Three of them carried out suicide explosions and a small group of them are resisting against security forces,' General Mohammad Zahir Azimi told selfnews. Surging violence has underscored the vulnerability of the Western-backed government ahead of nationwide polls on August 20, when Afghan President Hamid Karzai stands for re-election. 'There are casualties but at this moment we don't know exactly how many people have been killed and injured,' Azimi said. 'They are armed with AK-47s and rockets. They are surrounded in a building from where they resist.' At least one of the bombers on Saturday detonated a car rigged with explosives in front of the police headquarters, but that blast caused no casualties. It was the third suicide bomb and gun commando-style assault on Afghan government targets in the east this week after six suicide bombers disguised as women tried to storm offices and a military base killing five people on Tuesday. The Taliban have increasingly resorted to coordinated suicide and gun attacks, which mimic the Mumbai attacks last November, in their fight against the government and its Western military allies deployed for nearly eight years. A Taliban spokesman identifying himself as Salahuddin Ayoubi called selfnews to claim responsibility for the attacks on behalf of the militants. 'We sent four suicide bombers who have attacked several government offices,' the spokesman said but gave no further details. Their targets included the provincial court, the attorney's office, a government guesthouse and a military barracks, Azimi said. Khost has become one of the most dangerous cities in Afghanistan over the last six months and the scene of repeated deadly attacks. The eastern province is just across the border from Pakistan's wild Waziristan tribal region, where US and Afghan officials accuse Islamist militants of plotting attacks on troops across the border. With the Taliban-led insurgency at its deadliest since the US-led invasion of 2001, the United States has ordered an extra 21,000 soldiers to Afghanistan in a bid to stabilise the country ahead of the August elections. The military said Saturday two NATO soldiers and more than a dozen rebels had been killed in separate incidents in Afghanistan. Western military casualties have hit record levels during the eight-year war with British and US troops conducting a massive offensive against the Taliban in the south, albeit as violence has spread increasingly north and east. According to independent website -- www.icasualties.org -- which counts military deaths in Iraq and Afghanistan, 66 foreign soldiers have lost their lives in Afghanistan this month, the deadliest since 2001. A total of 222 have lost their lives this year, the website reported. Five people died on Tuesday when eight suicide bombers, some dressed as women and carrying guns, tried to storm official property in two Afghan cities, exposing the vulnerability of the government in the run-up to key elections. Afghan authorities said later that police arrested seven would-be suicide bombers, who would have inflicted mayhem in further coordinated strikes against the Western-backed government. 