WFP said one of its chartered ships carrying food aid for the Red Crescent Society in Libya had returned to Malta because of security concerns at the Libyan port of Benghazi.
Rebel fighters are battling for control over Benghazi as they come under attack by forces loyal to Libyan leader Moammar Gadhafi. WFP said the repeated aerial bombardments near the port city are forcing cargo ships to turn away.
WFP Executive Director Josette Sheeran said her agency was exploring its options to get food aid into Libya. Food aid is on its way to the Tunisian border, she said, but safe humanitarian passages were needed in Libya.
"We are exploring every possible humanitarian corridor to be prepared in case needs escalate," she said in a statement. "We have already airlifted high energy biscuits to the Tunisian border and we are in the process of pre-positioning wheat in the same area."
Sheeran said WFP has launched a three-month, $39.2 million program to provide food assistance to Libyans.