Unknown assailants attacked a compound of the International Committee of the Red Cross in the Libyan port of Misrata on Sunday with grenades and rockets, forcing it to suspend its work there and in the eastern city of Benghazi, the agency said.
The ICRC said seven of its aid workers were inside their residence when it came under attack. No one was hurt, but damage to the building was extensive.
It was the fifth time in less than three months that violence was directed against the independent aid agency in Libya, the ICRC said in a statement, which stressed its neutrality.
"Given the circumstances, we are forced to announce, with considerable regret, that we will be suspending all our activities in Misrata and Benghazi and that our delegates in those cities will be temporarily relocated," said Ishfaq Muhamed Khan, the head of the ICRC's delegation in Libya.
In Geneva, spokesman Jean-Yves Clemenzo said that the seven staff had withdrawn to its delegation in the capital Tripoli. "We do not know who carried out the attack. Grenades and RPGs (rocket-propelled grenades) were used, it was a serious incident," he told Reuters.
The ICRC has a humanitarian mandate to protect people affected by armed conflict and other situations of violence and to provide them with assistance, it said.
"The ICRC is not involved in political or religious activities of any kind, neither in Libya nor anywhere else," it added. Clemenzo said that the organization was sometimes mistaken for a religious movement, which is not the case.
Throughout the revolt last year that ousted Libyan leader Muammar Gaddafi, ICRC aid workers delivered food and medical assistance to civilians, including those trapped in Misrata, which was long held by rebels under siege by Gaddafi's troops.
"We are appalled by this latest act and by the deliberate targeting of our staff: they have put their lives at risk to serve the Libyan people both during and after the conflict," Khan said.