Yemen tribesmen released seven hostages, including four Syrian truck drivers, on Saturday after authorities agreed to free 13 of their clansmen jailed for weapons possession, a local official said.

"Four Syrian truck drivers employed by a Saudi company and three Yemenis, including a colonel, were freed in Tur al-Baha region" in the southern province of Lahij, the official, Abed Rabbo Ghanem, told AFP.

They walked free after authorities agreed to release from jail 13 tribesmen who had been arrested on charges of weapons possession, he said.

Ghanem added that reports earlier this week that Saudis were among the hostages were mistaken.

On Monday, a tribal chief told AFP that two Saudis were among the men abducted.

Tribes have an influential sway over Yemen and have been responsible for the abduction of hundreds of people over the past 15 years for use as bargaining chips with the authorities.

Almost all of them have later been freed unharmed.