An aid ship dodged Libyan government rockets and shells as it evacuated hundreds of migrant workers and wounded civilians from the besieged port city of Misurata on Wednesday, but it was forced to leave behind hundreds of others who were desperate to leave.

The Red Star 1, operated by the International Organization for Migration, finally docked to deliver humanitarian assistance and evacuate civilians, after waiting since Saturday because of shelling and mines that were laid in the harbor by forces loyal to Libyan leader Moammar Gaddafi.

Even as it docked, more shells landed just short of the port, killing five foreigners, including two young African children, waiting to be evacuated from a relief camp, witnesses said. Two Libyan civilians also died in shelling in Misurata on Wednesday.

“It was absolutely chaotic,” said rebel spokesman Mohamed Ali, who was at the port when the boat docked. “It’s so distressing seeing young children killed in this murderous way.”

The dead included a 3-year-old boy, a girl about 2 and their father. The children’s mother was also wounded.

“We were just sitting there when the bombs came down,” Saka Yossie, a 27-year-old Ghanaian, told the Associated Press. “They died right in front of us.”

Yossie said he’d spent six weeks in the camp, sleeping in a tent with little food and water. “Now I thank God for taking me from this place,” he said as he stepped onboard the ferry.

The Gaddafi regime has threatened to attack any ships using Misurata’s port because the rebels also use the Mediterranean Sea to bring in arms, ammunition and fighters.

The government says aid can be delivered over land but has not offered any pause in the shelling of Misurata to allow that to happen. Vegetables in the city ran out weeks ago and supplies of other foods and medicines are running low, with a particular shortage of psychiatry and oncology drugs and painkillers, doctors say.

In the scramble to leave, the the Red Star 1, which had hoped to evacuate 1,000 African and Asian migrant workers, took away between 700 and 800. “Hundreds of Libyan civilians had also tried to board the ship in desperation to get out of Misurata,” the International Organization for Migration, an intergovernmental body, said. “But with a limited capacity, the ramp of the boat had to be pulled up so that the ship could pull away from the dock in safety.”

The U.S. State Department condemned the “brutal attacks on civilians” and the delays to the relief effort caused by the mining and shelling of the Misurata port.

Gaddafi’s government should “cease hostilities in [the] Misurata port and . . . allow the International Organization for Migration and other organizations to provide much needed relief and evacuation services to civilians caught up in the Libyan conflict,” State Department spokesman Mark Toner said in a statement.

At a meeting of the United Nations Security Council, the chief prosecutor of the International Criminal Court said Gaddafi’s security forces had systematically attacked and killed peaceful protesters since their crackdown began in mid-February.

Luis Moreno-Ocampo said that civilians in government-controlled areas are subject to systematic arrests, torture, killings and enforced disappearances, and said he would seek arrest warrants in coming weeks against three Libyans who he said appear to bear “the greatest criminal responsibility” for crimes against humanity. He did not name them.

“It is welcome news,” said Jalal el-Gallal, an opposition spokesman in the rebel stronghold of Benghazi. “For so long this man [Gaddafi] broke every international law you can think of and blamed the Libyan people for it. Now it is clear it wasn’t the Libyan people.”

Gaddafi has not been seen in public since a NATO missile attack late Saturday on a house in an upscale residential neighborhood of Tripoli. The Libyan government says one of Gaddafi’s sons and three of his grandchildren died in the attack but that the Libyan leader escaped unharmed and has returned to work.

“[The] best intelligence we have is that he is still alive,” CIA Director Leon E. Panetta told NBC News.