Kabul, Aug 23 : The German army has said that a member of the Afghan security forces was killed in a gunfight at the north gate of the Kabul airport on Monday, the media reported. A statement said that the US and German troops had been involved alongside the Afghan guards - with three other Afghans injured in the incident, the BBC reported. It's not clear who started the fighting and German officials said the three Afghans were hurt by "unknown attackers". The Afghan forces are thought to be part of an army contingent who have been helping international forces, having refused to surrender to the Taliban. On August 21, the US advised its citizens to avoid the area because of potential terror threats. The airport has been a scene of chaos for much of the week since the Taliban takeover of Kabul, with thousands of Afghans and foreign nationals trying to flee the country. A NATO official told a wire service on Sunday that at least 20 people had died in and around the airport since last weekend - including from crushing and shooting incidents. /IANS