Fighters backing internationally recognised Ivory Coast president Alassane Ouattara Thursday seized San Pedro, the world's biggest cocoa exporting port, in an offensive to take control of the country.
They took the port city in the early hours of the morning after sweeping southwards from strongholds in the north since Monday, seizing several other towns that had been under the control of forces loyal to Laurent Gbagbo, who refuses to cede power.
Ouattara's camp meanwhile warned Gbagbo to step down, saying otherwise their next target would be the country's economic capital Abidjan.
"They have total control of the town since 4:00 am," a resident in San Pedro said.
"They launched an offensive between 10:00 pm and 1:00 am and afterwards they carried out searches. Currently they are patrolling the town on board 4x4's armed with Kalashnikovs" and rocket-launchers.
"They control the port, all the strategic sectors of the town," he added.
Ivory Coast is the world's top cocoa producer and exporter but the industry has been strangled by international sanctions trying to choke off Gbagbo's economic power and force him to step down from the presidency.
Gbagbo, who refuses to accept he lost November elections, came under more pressure when the United Nations Wednesday followed the European Union and United States in imposing sanctions against him and his leadership.
In San Pedro, pro-Ouattara fighters had met with local government authorities late Wednesday, an official said.
"They came to pay a visit at the home of the prefect and assured us they were there for the security of the town," said the official from the prefecture.
Witnesses reported militia supporting Gbagbo had looted several businesses and burned a police station after stealing weapons.
The noose tightened around the embattled strongman's regime as pro-Ouattara fighters seized the political capital Yamoussoukro on Wednesday, reportedly to jubilant scenes.
From there they pushed further south until by late Wednesday they had entered San Pedro.
Ouattara's camp, weary of four months' of fruitless diplomatic initiatives, declared all peaceful solutions "exhausted" as they launched their offensive on Monday.
They now controlled three quarters of the country, said Ally Coulibaly, Ivory Coast's ambassador to France -- appointed by Ouattara.
The country's main city Abidjan however appeared to still be largely under Gbagbo's authority.
Late Wednesday Ouattara's prime minister Guillaume Soro told France24: "Gbagbo has only a few hours to leave, otherwise we will march on Abidjan and it will become a lot more complicated for him."
The UN resolution, proposed by France and Nigeria, made the first explicit call by the 15-nation Security Council for Gbagbo to stand down in favour of Ouattara, whom the United Nations and virtually all countries say won the presidential election.
It authorised a travel ban and an assets freeze against Gbagbo, his wife Simone and three of his closest associates.
"Gbabgo must go, it is the only way to avoid a full-fledged civil war and maybe bloody violence in the streets of Abidjan," France's ambassador Gerard Araud said.
"The unthinkable is taking place before our eyes," said Nigerian ambassador Joy Ogwu, highlighting killings and widespread rapes. "The unrest is spiralling out of control," she told the council.
Election-linked violence has left at least 460 people dead with as many as one million fleeing their homes, according to UN agencies, amid allegations of human rights abuses on both sides.
South Africa, which voted in favour of UN sanctions on Gbagbo, warned Thursday Ivory Coast was "rapidly sliding back into a civil war".
"The continued senseless killing of civilians, threats and acts of intimidation as well as the rising numbers of refugees is a serious violation of human rights," it said, calling for an end to the violence.