ANKARA (REUTERS) - Turkish troops returned fire after coming under attack along the Syrian border overnight as more than 1,000 suspected smugglers, including 150 on horseback, tried to cross into Turkey from Syria, the military said.

The incident on Turkey's long Syria frontier, where tensions have been on the rise over the past couple of months, follows a string of similar confrontations between Turkish soldiers and hundreds of people described by the military as smugglers.

Syrian refugees fleeing from the civil war in their homeland often cross over the frontier in large numbers and Turkish officials have conceded smugglers sometimes intermingle with the refugees to use them as cover.

The military said it spotted between 750 and 1,000 people on foot, a separate group of 150 people on horseback, and some 40 vehicles forming a line around 300m along the border near the Turkish village of Kusakli in Hatay's Reyhanli district.

The troops deployed armoured vehicles and a tank along the frontier to block the group from crossing and issued warnings in Turkish and Arabic to try to keep them back, the military said.

The security forces then intervened, the military said, without elaborating. Some 15 to 20 rounds were fired with a pump-action rifle from Kusakli, prompting the soldiers to return fire.

The military did not specify whether smugglers or villagers opened fire. Following the army's warning shots, the smugglers left the area. Some 35 containers of petrol were found.