Gaddafi shells rebel supply route near Tunisia: report (VIDEO)

Libya's military has been shelling a route used to ferry supplies from across the Tunisian border to rebels fighting Muammar Gaddafi's forces in western Libya, according to a report.

The news comes a day after a funeral service for Gaddafi's son, who Tripoli says was killed during NATO’s intensifying air campaign.

Several thousand people attended a funeral in Tripoli for Gaddafi’s son, Saif al-Arab, 29, and three of the dictator's grandchildren, purportedly killed in the Apr. 30 NATO air strike on the leader’s compound. Anti-aircraft fire thundered in the background while mourners flashed victory signs and chanted for revenge, the Associated Press reported.

However, doubts have been raised about Tripoli's claim that Gaddafi family members — or indeed anyone — was killed in the attack on Bab al-Aziziya compound, which Gaddafi and his wife reputedly narrowly escaped. Gaddafi's regime has used the attack to lend support to its claim that the NATO forces are overstepping their legal mandate.

Rebels based in the eastern mountains, meantime, told the Associated Press Tuesday that forces loyal to Gaddafi have been firing dozens of rockets at the road to disrupt supplies coming from the Dhuheiba crossing.

The Libyan leader, whose forces control most of western Libya, has been fighting rebels in the east since an uprising against his rule began in February.

Meanwhile, outside pressure for Gaddafi to resign has been mounting.

Turkish Prime Minister Recep Tayyip Erdogan said Tuesday, a day after Turkey shuttered its embassy in Tripoli and evacuated its diplomats to Tunisia, that the Libyan leader must "immediately step down."

Turkey traditionally has had close trade ties with Libya, and that relationship has helped it serve as a mediator, most recently when four New York Times journalists were captured and held by Gaddafi's forces.

"A new period started in the history of Libya. Words ran out on the Libya matter," Erdogan told reporters in Istanbul, CNN reported. "At this point what needs to be done is for Muammar Gaddafi, who is holding the government in Tripoli in Libya, to leave power immediately and to fulfill his historical and humanitarian responsibility."

Erdogan promised to propose a plan to end the conflict in Libya during talks in Rome later this week, without giving details. Past attempts to mediate a settlement have failed to make headway as Libyan rebels rejected proposals that didn’t involve Gaddafi’s immediate departure.

The Wednesday meeting of the so-called Libya Contact Group — formed at an international conference of Foreign Ministers in London in March — will allow the U.S. to discuss with its international partners the ongoing implementation of U.N. Security Council resolutions 1970 and 1973, the U.S. State Department said, RTT news reports.

Secretary of State Hilary Clinton will conduct a series of bilateral meetings, including with Italian Prime Minister Silvio Berlusconi, President Giorgio Napolitano, and Foreign Minister Franco Frattini during the three-day meeting.