Syrian rebels were in control of three border posts along the frontier with Turkey on Sunday, a diplomat and reports said, as an amateur video showed armed men celebrating the takeover of one crossing.

The rebels now controlled Jarabulus, Bab al-Hawa and Al-Salama border crossings along the Turkish frontier, a Turkish diplomat and Turkey's Anatolia news agency said.

The Al-Salama border post, north of the Syrian city of Aleppo, was taken over on Sunday at 0400 GMT, the diplomat said on condition of anonymity.

The Bab al-Hawa crossing was taken over on Thursday, while the Jarabulus post came under the control of the rebels on Tuesday.

Amateur video distributed by the Syrian Observatory for Human Rights watchdog group showed armed men carrying the flag of the Syrian uprising at the Al-Salama border crossing.

The crossing faces the southern Turkish border post of Oncupinar in the southern Kilis province.

The video footage shows one fighter, who identifies himself as spokesman for the "Northern Storm Brigade" of the rebel Free Syrian Army, said the border post was now under their control.

"Bab al-Salama has been liberated from the hands of Assad's mafia, after a suffocating siege on them," he said, without giving his name.

Regime forces "withdrew after suffering losses," he added, describing Turkey as a "sister nation."

Several men standing behind him hold up their weapons to celebrate, chanting: "Allahu Akbar! (God is greatest)."

The man called the takeover of the outpost a step on the road "to liberate Aleppo, and then Damascus, and then the presidential palace."

Turkish news agency Anatolia reported that rebel fighters took Al-Salama post after hours of fighting during the night, and that the sounds of the battle could be heard from the Turkish side of the border.

On Tuesday, rebels took control of the Jarabulus border post, north of Lake Assad in Aleppo province, which faces the Turkish Karkamis post in the Gaziantep, the Turkish diplomat said.

Syrian refugees housed in the Oncupinar camp on the Turkish side of the border took water and food to rebel forces, the news agency added, saying Turkish authorities had prevented people from crossing into Syria for security reasons.

Rebel forces gained control of the Bab al-Hawa crossing between Syria and Turkey on Thursday, but by Saturday evening, a group of some 150 foreign fighters calling themselves as Islamists were in control of the Bab al-Hawa post, an AFP photographer said.

Some of the fighters said they belonged to Al-Qaeda in the Islamic Maghreb (AQIM), while others claimed allegiance to a group called Shura Taliban.

They were armed with Kalashnikov assault rifles, rocket launchers and improvised mines.

The fighters identified themselves as coming from a number of countries: Algeria, France, Egypt, Saudi Arabia, Tunisia, the United Arab Emirates and the Russian republic of Chechnya.

There are seven functioning border posts along the nearly 900-kilometre (560-mile) frontier.