Libyan police arrested six Qataris at Benghazi airport on Saturday as they tried to board a plane to Turkey using forged Libyan passports and carrying almost $146,000, airport security sources said.

Western diplomats in Libya worry that Benina airport in the eastern city of Benghazi is being used by Islamists to travel to Turkey in order to join anti-government rebels in Syria.

Libyans do not need a visa for Turkey, which is linked to Benghazi by daily flights. Security is often lax at the small airport.

The six men were held as they were about to board a Turkish Airlines flight to Istanbul from where they had an onward booking to the Qatari capital Doha, one airport source said.

Five of the men were definitively of Qatari origin, while the sixth was suspected of being Qatari, the source said.

They had no checked in luggage but carried 180,000 Libyan dinars ($146,000), the officials said.

They were no more details immediately available.