Two suicide bombers attacked a British private security firm in a central neighborhood here Tuesday afternoon, engaging in a running shootout with guards before blowing themselves up and killing two of the company's Afghan drivers. The attack on Hart Security's Afghan headquarters pierced the usual bustle of the mostly residential Taimany neighborhood and served as another reminder that the capital is not immune from the insurgent violence plaguing much of the rest of the country. Afghan police officials confirmed the four deaths and said a security guard for the firm was taken to the hospital after being wounded in the attack. Witnesses and a shopkeeper next door to the firm described seeing two young men, perhaps teenagers, running through the streets with their faces hidden, shooting at the building and guards out front. The building was pockmarked with bullets, glass was shattered on upper levels above a security wall and a car near the building was singed. A bloody leg lay on one side of the street. Officials lifted the torso and legs of a second dead body and wrapped them in a plastic sheet. The attack came as the United Nations released data showing that civilian casualties in Afghanistan have risen 31 percent this year compared with last year. The report showed that the spike has been caused largely by increased killings by the Taliban and other insurgent groups, who have taken more violent actions, such as using car bombs and suicide bombers. U.N. staff recorded 1,271 civilian deaths and 1,997 injuries. Of those, insurgent forces were responsible for 2,477 casualties, while NATO and Afghan government forces accounted for 386. 'The job of the government is to fight with the terrorists in Afghanistan, but if our actions cause the casualties of civilians, it is not justifiable in any way,' Waheed Omer, spokesman for President Hamid Karzai, said at a news conference Tuesday. 'And we also want from the opposition group to stop the killing of civilians in Afghanistan.' Omer also reiterated Karzai's pronouncement last week that government will seek the disbanding of all private security firms in the country, which Omer said employed more than 30,000 well-armed, well-trained security officials. He called them 'thieves by day, terrorists by night' because they abuse their power and weaponry. A call placed to the Hart office was not answered. The company's Web site said it was founded in 1999 by Lord Richard Westbury. 'Hart's management team combines extensive experience in conventional and special forces military service and maritime expertise,' according to the site. The firm has offices in more than a dozen countries, but the address of the Afghanistan office was withheld from the site for security reasons. Special correspondents Javed Hamdard and Qadratullah Andar contributed to this report. 