Tripoli, Libya (CNN) -- Libyan leader Moammar Gadhafi's forces bombed key fuel depots in the contested city of Misrata Saturday, destroying six containers and causing a massive fire, a rebel spokesman said.
Meanwhile, in the de facto rebel capital, Benghazi, the Libyan opposition said Italy has agreed to arm the rebels.
Abdul Hafiz Ghoga, deputy chairman of the National Transitional Council, said opposition representatives have flown to Italy to finish the deal.
The Italian Foreign Ministry categorically denied it will send weapons to Libya. A press office spokesman said Italy will only go as far as sending non-lethal weapons such as satellite and radar systems to aid the rebels.
The rebels, intent on winning on the ground without foreign troops, have been asking for arms supplies as a grinding war rages in cities like Misrata.
Three green helicopters with the internationally recognized symbols of the Red Cross and Red Crescent were seen flying over Misrata's port early Saturday, said rebel spokesman Ahmed Hassan. He said Gadhafi's forces are using aid helicopters to bomb the city.
The fuel depots were located 2 kilometers from the port. The oil stored there was used for electricity and generator plants.
"We lost a lot of fuel which is used for the daily life of the city," Hassan said.
Misrata, the only city in western Libya held by the rebels, has been the scene of heavy fighting for weeks as Gadhafi's forces try to reclaim control.
The international community has accused Gadhafi of attacking his own citizens and NATO took control of airstrikes in late March to protect Libyans.
NATO said it struck ammunition facilities in the Misrata area Friday as well as other military targets in Tripoli, Zintan, Mizdah, Sirte, Ras Lanuf and al-Brega.
As time wears on, human rights groups have expressed increasing concern for besieged Libyans in Misrata.
Ealier this week, Amnesty International said Gadhafi's attacks in the port city may amount to war crimes.
A report issued by the monitoring group accused pro-Gadhafi forces of the "unlawful killing of civilians due to indiscriminate attacks, including use of heavy artillery, rockets and cluster bombs in civilian areas and sniper fire against residents."
It also documented "systematic shooting at peaceful protesters and enforced disappearance of perceived opponents, which can amount to crimes against humanity."
The scale of the relentless attacks that we have seen by Gadhafi forces to intimidate the residents of Misrata for more than two months is truly horrifying," said Donatella Rovera, Amnesty International's senior adviser who is currently in Libya.
CNN's Mitra Mobasherat and Amir Ahmed and journalist Livia Borghese contributed to this report.