A Taliban suicide car bomber has attacked a foreign military convoy in the Afghan capital, Kabul, injuring at least 16 people, Afghan officials say. The blast took place in heavy traffic on the airport road near the US embassy at about 08:00 local time (03:30 GMT). The Taliban said that they carried out the attack. The blast comes amid uncertainty over disputed presidential elections and over the withdrawal of most Nato troops by the end of this year. Witnesses told AFP news agency that a vehicle from the convoy was thrown off the road and destroyed by the blast. Foreign troops were seen giving first aid to blood-stained soldiers from the convoy. The nationality of the injured remains unclear. The targeted vehicle was carrying coalition soldiers and the explosion shook buildings across the centre of the capital. The blast took place close to the country's Supreme Court. Kawoon Khamoosh, who was not far from the bomb when it went off, said many people were in shock following the attack. He saw broken glass in nearby buildings and cars. Another eyewitness, Ahmad Ajmal, had a narrow escape. He told the Associated Press news agency: "When I got out of the vehicle and started walking, an explosion happened, the same vehicle I was in is there and destroyed." Taliban sources told reporters via e-mail and on Twitter that the group had carried out the attack. The two candidates vying for Afghanistan's presidency, Ashraf Ghani and Abdullah Abdullah, have been locked in a dispute over the results of the recent election, which was rocked by allegations of fraud. The two are now negotiating a power-sharing deal and met on Monday to discuss it. Correspondents say that Taliban insurgents have taken advantage of uncertainty over the presidential election to launch attacks. In July a Taliban suicide bomber killed four people, including at least three foreign security guards, in an attack on a key counter-narcotics building outside Kabul airport. That attack came days after security forces repelled an attack on Kabul airport by the Taliban.