U.S. Marines landed in Liberia on Thursday to assist West African peacekeepers in their efforts to bring stability to the war-ravaged country. VOA Correspondent Alisha Ryu, in the Liberian capital, Monrovia, witnessed the Marine deployment and the subsequent withdrawal of the country's main rebel group from Monrovia's seaport.

Hundreds of Liberians standing outside Roberts International Airport cheered wildly when the first set of U.S. Marine helicopters swooped into view Thursday morning.

The helicopters ferried some 150 Marines and 50 other U.S. troops into Monrovia from American warships, which have been off the coast of Liberia for the past two weeks.

At the airport, the U.S. Ambassador to Liberia, John Blaney, told reporters the Marines have a mandate to assist the Nigerian-led West African peacekeeping force, known as ECOMIL. The force is working to restore security and the free-flow of humanitarian aid to tens of thousands of desperate people.

Until now, the United States has been mainly providing ECOMIL financial and logistical assistance.

"I think this will be a very important step to help the people of Liberia, as President Bush has said. We want to help those who are suffering here," he emphasized. "By working with ECOMIL, we're going to make it happen."

In the city of Monrovia, tens of thousands of people, anticipating Thursday's noon deadline for the rebel handover of the city's seaport jammed both sides of a bridge that for weeks has marked the front-line of the divided capital.

Early last month, Liberia's main rebel group, called LURD, Liberians United for Reconciliation and Democracy, captured the port from forces loyal to exiled former Liberian leader Charles Taylor. The rebel offensive cut off the flow of food to more than half of Monrovia's one million residents.

As Marine attack helicopters and Harrier jets flew overhead, a top rebel spokesman relinquished the port area to U.S. and West African officials with a handshake during a small ceremony in the center of the bridge.

Minutes later, rebel fighters left the port and headed north toward the Po River, outside of the city. Many fighters, still carrying their guns and rocket launchers, carried away sacks of rice, stereos and other looted items in pick-up trucks and moving vans.

The commander of the West African peacekeeping force, Nigerian Brigadier General Festus Okonkwo, says the port will not be open to the public, until the area is secured.

He says his troops are also preparing to take control of Liberia's second largest city, Buchanan, from the country's smaller rebel group, known as MODEL, the Movement for Democracy in Liberia.

"This is the first stage of it. We're finished with the LURD. And by this weekend, possibly next week, I will be with MODEL," he said. "I've spoken with them, and they've given me assurance they will cooperate with us."

A cease-fire has held in Monrovia since West African peacekeepers began arriving earlier this month. But sporadic fighting has persisted in Buchanan.

U.S. Ambassador Blaney says the southern rebels have now agreed to withdraw several kilometers away from Buchanan to a new cease-fire line, providing another port for relief supplies.