ABIDJAN/ABUJA (Reuters) - A peaceful or swift resolution to Ivory Coast's post-election crisis looked increasingly unlikely on Tuesday, with mediators speaking of a "stalemate" and Laurent Gbagbo's rivals saying force was needed to oust him after talks had failed. Leaders of West African regional bloc ECOWAS and the African Union ended meetings in Ivory Coast on Monday, having failed to convince Gbagbo to cede power to Alassane Ouattara, who is widely recognised as winner of a November 28 presidential election. "There is still a stalemate, so the team is still meeting now," Nigeria's President Goodluck Jonathan, also head of ECOWAS, told reporters in the Nigerian capital Abuja. "We will continue with the discussion ... but the ECOWAS position ... after our last meeting still stands." ECOWAS has previously warned that it is prepared to use "legitimate force" to oust Gbagbo if he does not step down. Ouattara's camp said talks had failed, leaving only force. "No I don't think there was any progress," said Patrick Achi, a spokesman for Ouattara's government, which is holed up in a hotel protected by UN peacekeepers. "The only thing left is ... the military preparation." The visit by four leaders representing ECOWAS and the African Union follows a previous, unsuccessful trip last week. Rebels who still run the north of the country, seized during the 2002-3 war that divided the nation, have backed Ouattara. "The next diplomatic shot might be after ECOWAS has pre-positioned some heavy military muscle nearby and Gbagbo knows this is it," said a diplomat following the process. ECOWAS has previously sent a force into conflicts in Liberia and Sierra Leone. However, in these cases they were invited by governments in place and West African nations will be wary of being bogged down in fighting with Gbagbo's soldiers. Meanwhile other concerns, including elections in Nigeria in April and the prospects of reprisal attacks on millions of their citizens in Ivory Coast, are likely to factor in decisions. "I just don't see what could change. The US has been putting pressure on the Nigerians to intervene but I don't think he (President Jonathan) could go for that before presidential elections in his own country," said Standard Bank's Samir Gadio. French President Nicolas Sarkozy said his troops would not meddle in Ivory Coast, a former colony. Asked if any face to face meeting between Gbagbo and Ouattara was possible, Achi replied: "Never, ever. As long as he will not be recognised as the elected president of Ivory Coast, he will never meet with president Gbagbo." While mediation was going on, armed conflict between rival tribes seen as being pro-Gbagbo and pro-Ouattara erupted in west Ivory Coast on Monday, killing at least 3 people and wounding many with gunshots, witnesses and a security official said. It was not clear if the clashes between Ouattara's Dioula tribe and the Gurer, seen as pro-Gbagbo, was election linked. Ouattara's party also said police raised his headquarters overnight. "I saw two people killed. The police chased everyone out and arrested some," said Hermane Kouadio, an occupant. Police spokesman Honore Diagouri said he was not aware of it. A Reuters reporter saw the building surrounded by police. Over 170 people have been killed since the elections, which were meant to reunite a country and deliver a stable government. Diplomats say have been killed by death squads targeting Ouattara supporters at night and hundreds more have been abducted. Gbagbo's camp denies any involvement. Gbagbo, who has the backing of the country's top court and the army, has shrugged off pressure to step down and accused world leaders of interference in Ivory Coast's affairs. A US official said on Monday Washington was not hopeful for a swift solution but Gbagbo was welcome to seek exile there. The UN has said Gbagbo may be criminally responsible for rights violations, including killings and kidnappings, and diplomats say any deal would need to involve immunity. Ivory Coast missed a nearly $30 million interest payment on its $2.3 billion Eurobond due on Friday but it is not yet in default because of a 30-day grace period. "Even if Ivory Coast defaults, if the situation improves in a few months, the new government can go to the bondholders and reschedule. They won't have to issue another," Gadio said. The crisis has not yet hurt Ivory Coast's main export, the world's largest cocoa crop, with deliveries matching last year's, although a return to war would be more disruptive.