Police backed by gangs of youths have ransacked at least 10 houses belonging to ministers and other allies of the internationally recognised president of Ivory Coast, according to witnesses.

The raids came amid worsening tensions between Alassane Ouattara and the sitting president, Laurent Gbagbo, whose refusal to step down has pushed the west African country to the brink of civil war.

As Ouattara and his cabinet-in-waiting remained under UN guard at a luxury hotel, their homes were reportedly targeted by Gbagbo's elite paramilitary police force, Cecos. A Cecos truck carrying a fridge left the house of Ouattara's finance minister, Charles Koffi Diby, later returning for a large safe, said a witness.

Dozens of teenagers smashed the doors and windows of the house and left wearing suits and robes, and carrying dishes and other valuables, according to the witness, who asked not to be identified for fear of retribution.

The looted houses belong to ministers and mayors in Ouattara's Rassemblement des Républicains (RDR) party, as well as to their family members and businessmen perceived as being pro-Ouattara.

Ami Toungara, Ouattara's women's issues adviser, said her house was looted and burned on Friday, and that the police are targeting people they know to be at the Golf hotel, where Ouattara has been besieged by troops, and unable to protect their houses. Toungara said that after the valuables were taken from her house, the raiders made off with tanks of cooking gas and bags of rice. "They stole a back massager and we later found it in the garden," she said.

Amadou Coulibaly, another Ouattara adviser, said that police had recruited youths to participate in the raids. "They're trying to instil an atmosphere of terror," he said. "But you can't do more than what they've already done, firing on unarmed women. They're getting desperate."

Coulibaly was referring to an incident last week in which Gbagbo's security forces opened fire with machine guns on unarmed women taking part in a political demonstration. Six were killed on the spot, and a seventh died in hospital. US state department spokesman Philip Crowley denounced the killings as "morally bankrupt".

Analysts fear that Ivory Coast's crisis will spill over into all-out civil war. Nearly 400 people have been killed since November's election, according to the UN. It also says more than 200,000 people have fled fighting in Abidjan in the last week, and more than 70,000 have crossed into Liberia.

In an attempt to restore order, the UN received two helicopter gunships last week and is awaiting the arrival of peacekeepers to bolster its force of 9,000.

Jacques Franquin, head of the UN's refugee agency, told the BBC: "Certain areas of Abidjan are truly in a situation of war with the population fleeing ... The situation is deteriorating rapidly."

Charles Ble Goude, a minister in Gbagbo's government who is also the leader of the hardline Young Patriots, last week called on "real" Ivorians to protect their neighborhoods, block all UN vehicles, and denounce foreigners. Hundreds of barricades have sprung up in neighbourhoods across Abidjan.

Meanwhile, fighters loyal to Ouattara said they captured the western town of Toulepleu, but Gbagbo's military said fighting continued.

"Since 14.10, the town of Toulepleu has been under the control of the New Forces [anti-Gbagbo rebels]. We managed to seize some arms," Mara Lassine, military spokesman for the rebels in the western zone, told Reuters by telephone.

"The combat continues, and it's difficult to know the toll," said an Ivorian army captain loyal to Gdagbo, who could not be named. "There are a lot of displaced. But the town is not yet taken. There is still fighting going on."

The fighting started on Saturday in one town in western Ivory Coast reputed to be a pro-Gbagbo stronghold, sources said. "It is true that many young people from the border towns were recruited by both forces in Ivory Coast," a resident in the Liberian town of Dialah was quoted as saying.