Fighting raged in the streets of Ivory Coast's main city of Abidjan on Tuesday as forces loyal to President-elect Alassane Ouattara targeted the presidential palace, where renegade incumbent President Laurent Gbagbo and his family are reportedly taking refuge in a basement bunker.

Two generals close to Mr. Gbagbo, meanwhile, are holding talks to work out the conditions under which he could surrender, said French Prime Minister François Fillon.

Gbagbo's top general, Phillippe Mangou, has called for a cease-fire and asked the United Nations for protection, UN spokesman Hamadoun Touré told Bloomberg.

The attack on the presidential palace comes after an unusual intervention by helicopter gunships of the UN peacekeeping force in Ivory Coast, as well as members of the French “Licorne” military force stationed in that country. The use of "all necessary measures" to protect civilians and seize heavy weapons was approved by the UN Security Council and requested by UN Secretary-General Ban Ki-moon, after what the UN called an “intensified” use of heavy weapons against civilians by Gbagbo’s troops.

"In the past few days, forces loyal to Mr. Gbagbo have intensified and escalated their use of heavy weapons such as mortars, rocket-propelled grenades and heavy machine guns against the civilian population in Abidjan," Mr. Ban said from New York.

Regional groups such as the Economic Community of West African States (ECOWAS) have demanded military action to remove Gbagbo. He refused to step down from power after losing a Nov. 28, 2010, runoff election that was deemed free and fair by the African Union, the United Nations, and others. But other African states have condemned foreign intervention, including that by the African Union, which has attempted numerous mediation efforts, all of which have failed.

The AU’s last mission, a panel of five presidents that included South African President Jacob Zuma, called on Gbagbo to step down, a move that Gbagbo refused.

Death toll mounting

With the stalemate slipping into an all-out civil war, the death toll has mounted, with civilians bearing the brunt.

UN observers counted some 800 casualties in the Western Ivorian town of Duekoue alone, where Gbagbo’s forces fled and Ouattara’s forces took over late last week in a lightning offensive. Both sides blame each other for the massacre. In Abidjan itself, the nation’s largest city, controlled until recently by Gbagbo’s troops, the death toll had been up to 500 over the past four months, but that toll will surely increase as troops from both sides fight street by street.

In a city with no news outlets – the pro-Gbagbo state TV station has been shut down since Ouattara’s forces arrived – rumors have run rife through Abidjan.

Some have claimed that Gbagbo is negotiating with Ouattara’s people to surrender. Others talk of gross atrocities by undisciplined fighters from both sides, as well as ad hoc militia groups such as Gbagbo’s “Young Patriots” and Ouattara’s “Invisible Commandos."

Civilians targeted

Reporters along the Liberian border have found consistent and compelling reports of massive killing of civilians; refugees in Liberia and displaced people huddled in church grounds blame the forces of Ouattara for the killings.

Ouattara’s spokesman, Alain Lobognon, denies the charges and calls for an independent investigation by the International Committee of the Red Cross and the UN.

“An impartial international inquiry is required as early as possible,” Mr. Lobognon said in a statement, “with the participation and collaboration of the leaders of the Forces Nouvelles [fighters loyal to Ouattara], to locate all those responsible and contribute to finally putting an end to impunity.”

What is certain is that civilians in Duekoue are clustering in places of safety that are rapidly growing beyond the capacity of aid organizations to manage. Civilians in Abidjan are afraid to venture outdoors, and food and medicines are running short, even in hospitals. Meanwhile, electricity and water supplies are increasingly difficult to find.

"We get telephone calls asking us to come pick up wounded people and patients, but it's impossible to move around," said Dr. Salha Issoufou, Doctors Without Borders' head of mission in Abidjan, in a press statement.