The mayor of the southern Turkish town of Akçakale in Şanlıurfa province, Abdülhakim Ayhan, said 12 people, including civilians, were wounded in the clash at the Akçakale border gate, opposite Syria's Tel Abyad gate.
Ayhan told reporters that a group of at least a thousand Syrians wanted to enter into Turkey without their passports and they started throwing rocks at a Turkish police station and set some border police cabins on fire in no-man's land when they were refused entry. Ayhan said the border security thought the situation had settled down but unidentified people opened fire, injuring several police officers.
Turkey deployed dozens of security forces to the area in response to the clashes. Firefighters were dispatched to extinguish the fire and tensions are still running high in the border area.
Şanlıurfa health official Erdoğan Duran told reporters that at least 12 people were injured in the incident. He said two police officers who were critically wounded were taken to central Şanlıurfa but other injured people are currently being treated in Akçakale hospitals.
He stated that seven of the 12 injured people were wounded by fire and the other five were injured during the brawl. Duran added that one of the people shot is a soldier while two others are police officers Ferhat Avcı and Mehmet Yenenci. The other four citizens who were injured by the gunfire have not been identified.
Avcı was first taken to Akçakale State Hospital but later transfered to Mehmet Akif İnan Education and Research Hospital. But doctors failed to save him.
A Syrian opposition activist said two opposition fighters were killed in the clash, but a Turkish official, who spoke on condition of anonymity, said the Syrians were smugglers and the five wounded were guards.
Fighters from the Free Syrian Army, a loose collection of army defectors and volunteers battling President Bashar al-Assad's forces, regularly cross from Turkey, where they have been given sanctuary, into Syria to launch attacks on the army.
Smugglers and opposition fighters also cross over to carry supplies like medicine and blankets to fighters inside Syria and to bring back wounded fighters and civilians as well as refugees into Turkey.
Still photographs showed smoke rising from the border crossing, with a fire engine at the scene. One photograph showed a wounded man being loaded onto an ambulance. Broadcaster CNN Türk said cars at the crossing were set on fire.
Turkey is now sheltering more than 300,000 Syrians who have fled the fighting in their homeland, most of them in camps along the 900-km (560-mile) frontier, and is struggling to keep up with the flow of new arrivals.
Ankara has denied previous reports that it has stopped entry to Syrians trying to cross into Turkey, saying it operates an open door policy but that at times it need to regulate the flow of refugees across the border.
The UN refugee agency criticised Turkey in March for sending home at least 130 Syrians in what some witnesses said were forced evictions following a riot at one refugee camp. Turkey denied it deported the Syrians.
The incident on Thursday was a reminder of the strains faced by neighboring countries as violence from the civil war in Syria, now into its third year, spills across its borders.
In October, five Turkish civilians were killed in Akçakale when a mortar bomb fired from Syria landed on their house, prompting Turkey to fire back across the frontier.