A gunman shot dead a Swedish-British journalist in central Kabul on Tuesday in an unexplained daylight murder that shocked the small international community living in a city on alert ahead of elections. Taliban militants denied responsibility for the shooting, which occurred in an upmarket district of the Afghan capital close to a restaurant where the insurgents killed 21 people, including 13 foreigners, in an attack in January. Sweden's ambassador to Afghanistan, Peter Semneby, identified the dead man as Nils Horner, 51, a journalist for Swedish national radio. "He had British nationality in addition to his Swedish nationality. His family has been informed," Semneby told AFP. Police said Horner's driver and translator were being questioned but the attackers had not been caught. "Security forces are on the hunt to find the perpetrators," a statement from the Kabul force said. - Experienced reporter - A witness at the scene described hearing a single gunshot before seeing Horner fall to the ground, and a doctor at Kabul's emergency hospital said he was dead on arrival. "There were two guys who ran away. They were perhaps in their 20s and security guards chased them as they ran away," the witness told AFP on condition of anonymity. Security forces cordoned off the street, where blood could be seen on the ground. Horner, hired by Sveriges Radio in 2001, was an experienced reporter who had been in Afghanistan to witness the fall of the Taliban in 2001 and in Iraq during the war in 2003. He also covered the 2004 Indian Ocean tsunami. "Nils was one of our absolutely best and most experienced correspondents and what happened to him today is terrible," Sveriges Radio chief Cilla Benko, said in Stockholm. "He was in Kabul three to four times a year. He knew the town and had carried out security checks. "He was shot in the back of the head in an area not considered to be a risk zone." - City on edge - According to journalists in Kabul, Hong Kong-based Horner arrived in the city on Sunday and had planned to stay about a week or 10 days. "Among Swedish journalists, he was a legend. In many ways, he died as he lived – in the middle of a news story," Johan Nylander, a Swedish freelance journalist based in Hong Kong, told AFP. "For many years he didn't even have an apartment. Hong Kong was the first place he put down his suitcase for half a decade." The killing comes less than a month before presidential elections in Afghanistan on April 5 and the withdrawal of NATO combat troops by the end of 2014 after 13 years of fighting the Taliban. On Tuesday, many of the Afghan capital's security forces were on duty at the funeral of Vice-President Marshal Mohammad Qasim Fahim, who died on Sunday. Horner had recently released a radio piece reporting on Fahim's death. The Taliban, who have led the insurgency against the Western-backed government since being toppled from power in 2001, denied the attack. "We checked with our mujahideen and they are not involved," Taliban spokesman Zabiullah Mujahid told AFP. "We don't take responsibility for this incident." Foreigners have been targeted before at guesthouses, luxury hotels and embassies in the heavily guarded city, but few have been gunned down in the street. The attack in January on the Taverna du Liban, a Lebanese restaurant popular with foreigners, was the deadliest on foreign civilians since the Taliban were ousted. One attacker detonated his suicide vest at the fortified entrance to the restaurant before two other militants stormed inside and gunned down diners and staff. After that attack, security restrictions were tightened on many of the diplomats, aid workers and journalists based in Kabul, where international staff often live and work in fortified compounds. The next president will face a testing new era as the Afghan army and police attempt to impose security without NATO assistance and as international funding declines. Among the front-runners in the election are Abdullah Abdullah, who came second in 2009, former foreign minister Zalmai Rassoul and former World Bank economist Ashraf Ghani.