The Russian Foreign Ministry said on Monday that arms smuggling to Syria from third countries is " unacceptable."

"Moscow repeatedly warned against the unacceptable arms smuggling to Syria, and warned those who expressed such ideas about the consequences of these actions," the ministry said.

Arms smuggling is especially dangerous as international terrorists and extremists are operating in the crisis-torn country, it said.

The ministry also pointed out that the Syrian opposition received hand grenades, anti-tank rifles and portable anti- aircraft warfare through third countries, such as Libya, Turkey and Lebanon, in addition to financial support from some Gulf countries.

"We have raised the issue of Libya at the UN Security Council Sanctions Committees, calling for an investigation into the Lutfullah-2 vessel that carried a batch of arms to Syrian rebels," it said.

In April, the Lebanese navy seized the Lutfullah-2 vessel, a Sierra Leone-registered ship, which carried several containers with small arms, grenade launchers identical to those used by rebels in Libya, and many explosives.

The consignment was reportedly to be destined for the rebels in Syria.