Four American and European cyclists have been run down and killed by a car in Tajikistan in what authorities said could be a terrorist attack. Two cyclists from the United States and one each from Switzerland and the Netherlands were killed in the incident on Sunday in the Danghara district near the border with Afghanistan. The men in the car then attacked the survivors with knives and guns, the interior ministry said. Three bikers from Switzerland, the Netherlands and France suffered injuries including stab wounds. “We are looking at versions that this was an accident, armed robbery, murder. The version of a terrorist act is also not being excluded,” interior minister Ramazon Rakhimzoda told journalists on Monday. At least one suspected attacker was killed while resisting arrest and at least one other was detained, the interior ministry said. A video reportedly taken at the scene showed what appeared to be the attackers' car turn around, accelerate and hit one of the fallen cyclists. A photograph showed a man receiving first aid next to another man lying on the ground. This video reportedly from the scene of the attack that killed 4 American & European cyclists in Tajikistan appears to show the car drive back around to hit one of them lying on the road @RFERLhttps://t.co/MwO03z3Url— Alec Luhn (@ASLuhn) July 30, 2018 President Emomali Rakhmon, whose hometown is near the site of the attack, expressed his condolences to the leaders of the United States, Switzerland and the Netherlands. Tajikistan has suffered from Islamic extremism in the past. At least 17 people were killed in 2015 when armed groups led by a deputy defence minister attacked police stations and an airport following the outlawing of the country's only Islamic political party. Hundreds of Tajiks left to fight with Isil in the Middle East, including the US-trained commander of the interior ministry's special forces. Drug smugglers and terrorists have often hidden in the mountains of the mostly Muslim, impoverished former Soviet republic, which suffered a civil war in the 1990s but is now trying to increase tourism. One of these groups, the Islamic Movement of Uzbekistan, fought US forces in Afghanistan as an ally of al-Qaeda and the Taliban and later pledged allegiance to Isil. Central Asia is an enticing but sometimes dangerous destination for adventure travellers. Rock climbing legend Tommy Caldwell and three other Americans were captured by Islamic militants just over the Kyrgyzstan border in 2000, an ordeal that only ended after Mr Caldwell pushed one of the hostage-takers off a 2,000-foot mountain.