DAMASCUS - At least 30 rebels were killed and tens of others wounded on Sunday, when a blast rocked a rebel-held border crossing between Syria and Turkey, activists reported.

A suicide bomber detonated his explosive belt at the border crossing in the northern countryside of Idlib, one activist group said.

Another activist group, the Syrian Observatory for Human Rights, also confirmed the explosion, saying the suicide bomber detonated himself inside a bus carrying rebel fighters from the Turkish territories into Syria.

The UK-based watchdog group said some Turkish border guards were killed as a result of the explosion, which indicates that the blast rocked at the Turkish side of the border crossing.

Several explosions rocked near the Turkish borders throughout the Syrian crisis, as part of the rebel-on-rebel tension.

The Syrian government has for long accused Turkey of facilitating the flow of rebel fighters from its territories into Syria.

The rebels' Jaish al-Fateh, or the Army of Conquest, are in control of much of Idlib, save for a couple of towns that are still inhabited by government loyalists.