Mortars killed up to 30 people in an Abidjan market Thursday, the United Nations said _ the latest in a string of street battles to grip the city as Ivory Coast's political crisis deepens.
Witnesses said the shells were fired from a military police base controlled by the country's sitting president into a neighborhood loyal to the man who beat him in last year's election, according to international observers.
The United Nations deployed a convoy of peacekeepers to the area soon after the shelling. It said in a statement that the peacekeepers had observed that Laurent Gbagbo's armed forces had fired at least six projectiles on and around the market "killing 25 to 30 persons and wounding 40 to 60 others."
Shells fell without warning on a market in front of the mayor's office in Abobo, a district held by fighters loyal to Alassane Ouattara. At one market stall, an elderly woman lost both her legs, a witness said.
Earlier in the day, pro-Ouattara fighters ambushed a police station in the Adjame district of Abidjan, though it was unclear whether anyone was killed.
Adjame resident Idrissa Ouedraogo said commandos loyal to Ouattara went around the Ouattara-friendly neighborhood and warned people to stay inside just minutes before the morning attack. Police loyal to Gbagbo were later seen fleeing the scene, he said.
Abidjan, Ivory Coast's biggest city, has seen daily battles between the supporters of each man claiming to be president for weeks, leaving hundreds dead. Fighting was initially confined to pro-Ouattara neighborhoods but has now spread across the city, breaking out in different locations each day.
"The situation is very serious there for the plight of civilians," said U.N. High Commissioner for Human Rights Navi Pillay, speaking in Dakar, Senegal, on Wednesday. "My staff are unable to visit certain sites ... they went to meet with victims where four children were killed and they had to literally run out from there because they then were threatened in return. The situation is grave."
The U.N. sent in armored patrols and helicopters after a grenade attack in the Attecoube district, across the street from their headquarters, on Wednesday. U.N. doctors treated 55 people, four of whom died, bringing the total number of deaths since November's election to 410.
In Yopougon, a slum reputed for its fervent support of Gbagbo, residents reported heavy fighting all day Wednesday and through the night.
"We can't sleep, the gunfire didn't stop until 5 a.m.," said Karim Coulibaly, a taxi driver who lives in central Yopougon. "(Pro-Gbagbo youth) go from house to house calling for people to join them in the streets _ no one went out."
Hundreds of roadblocks have sprung up around the city, making it nearly impossible to move around. Roadblocks run by the police or military tend to be professional, but others run by local youth often turn violent, with frequent reports of assaults on drivers, smashed windshields and extortion.
The violence reached a new level after Gbagbo rejected last week's African Union decision to endorse Ouattara's victory. The decision, which is supposed to be binding, is the latest in a half-dozen failed negotiation attempts and contributes to the widespread fear that now only violence will resolve the deadlock.
Fighters loyal to Ouattara have been stepping up their tactics. In the first months following the election, unarmed protesters confronted Gbagbo's police and were killed by the dozen. In February, a group calling themselves the "Invisible Commandos" emerged to protect Ouattara supporters. Now, after having taken control of the Ouattara strongholds of Abobo and PK-18, those fighters are moving south, closer to the commercial center of the city and the presidential palace.
Ouattara's camp denies that the Invisible Commandos act under their orders and draws a line between them and the New Forces rebels, who act as Ouattara's de facto army.
Those professional forces have been focusing their efforts far from Abidjan in the west. New Forces have taken four towns along the Liberian border in the last weeks, claiming to have cut off weapons smuggling and the recruitment of Liberian mercenaries.
The U.N. reports that more than 90,000 people have fled across the border to Liberia to escape the fighting. This is in addition to the 300,000 who have fled fighting in Abidjan.
In Brussels, the European Commission announced Thursday it would increase humanitarian aid for victims of the violence from euro5 million ($7 million) to euro30 million ($42 million).
The commission, which is the executive arm of the European Union, said the money would help people in need inside Ivory Coast, as well as refugees who have fled to neighboring countries.
A report released earlier this week by Human Rights Watch accused pro-Gbagbo security forces of war crimes, including killings, torture, rape and arbitrary arrest.
Officials from the Hague-based International Criminal Court are monitoring the events closely, said Deputy Prosecutor Fatou Bensouda. The ICC, however, cannot open an official investigation until it can protect the witnesses they expose, she said.
"If we are not in a position to protect them, it would not be a good time for us to intervene," she said. "We are monitoring (Ivory Coast) very, very, closely."
After more than three months of being blocked by pro-Gbagbo security forces, the U.N. was finally able to reach the site of an alleged mass grave this week, said local U.N. spokesman Hamadoun Toure. The found no evidence of a mass grave, he said, though he wasn't able to rule out that the bodies were moved before they got there.
Associated Press writers Anne Look in Dakar, Senegal, and Don Melvin in Brussels contributed to this report.