BRUSSELS/ABIDJAN: The European Union imposed sanctions on Ivory Coast incumbent Laurent Gbagbo Monday and his army briefly surrounded his rival's headquarters in a tense standoff. Gbagbo is in a power struggle with Alassane Ouattara, with both claiming victory in a Nov. 28 election meant to reunite the world's top cocoa grower after a 2002-03 civil war, but which has instead deepened divisions. Supporters of Ouattara, who enjoys broad international support after election commission results showed he won the vote, threatened to march into government buildings and state TV offices at the end of the week if Gbagbo stays put. Gbagbo and his supporters say the vote was tainted by massive fraud and intimidation, a claim supported by the country's top legal body which threw out hundreds of thousands of votes to give Gbagbo a win. Around 20 government troops armed with machine guns and grenade launchers were seen close to the UN-guarded hotel in Abidjan being used as a base by Ouattara. There was no comment on the deployment from the military, which backs Gbagbo. A Ouattara spokesman said the standoff followed an attempt by troops to set up a position near the hotel, before they were chased away by rebels backing Ouattara. Gbagbo soldiers also blocked access to two roads leading to the hotel. “I guess it is like a siege. They won't let anyone in at all,” said Ouattara spokesman Patrick Ache. A spokesman for the UN mission said its chief Y.J. Choi visited the scene and managed to calm tensions. “He went to where there were incidents and spoke to the parties,” Hamadoun Toure said, adding that the rebels had agreed to withdraw back to inside the hotel. In Brussels, EU foreign ministers agreed to impose sanctions on Gbagbo and his backers to deepen his diplomatic isolation. The 27-member bloc agreed to draft a list of officials deemed to be “obstructing the process of peace and national reconciliation ... and who are jeopardizing the proper outcome of the electoral process,” ministers said.