KAMPALA (Reuters) - Bobi Wine, leader of Uganda’s main opposition party, said troops raided its headquarters on Monday as staff tried to prepare a legal challenge to President Yoweri Museveni’s declared victory in an election last week. Wine, himself under house arrest, said party leaders were now on the run. “Our party office has been raided by the military and been cordoned off,” Wine told Reuters. “Everybody is being pursued.” Police spokesman Patrick Onyango said the National Unity Platform (NUP) office had been cordoned off for security reasons, but he gave no more details and did not say if troops had entered the premises. Wine, whose real name is Robert Kyagulanyi, said later on Twitter that the U.S. ambassador to Uganda was sent away from his gate after she tried to visit him. There was no immediate comment from the U.S. Embassy on the planned visit. The electoral commission declared incumbent Museveni the winner of the Jan. 14 election on Saturday, triggering protests in two areas. Wine, a former pop star-turned-legislator, came second and accused Museveni of winning by fraud.. In the election, where voters were also choosing members of parliament, Wine’s NUP won 61 seats. Five other opposition parties won 48 seats, giving opposition lawmakers in the next House 109 in total, a government statement said on Monday. The ruling party won 316 seats. Wine had appealed to youth to vote out Museveni, a 76-year-old in power since 1986. Wine’s songs have frequently criticised Museveni for corruption and nepotism, accusations he denies. Museveni, one of Africa’s longest-ruling leaders, has dismissed the allegations of fraud and said the election may turn out to be the “most cheating-free” in Ugandan history. The government wanted to disrupt documentation of voting fraud, NUP spokesman Joel Ssenyonyi said. Slideshow ( 3 images ) “They don’t want work to continue at our offices because they know that we are putting together evidence to show the world how much of a fraudster Museveni is.” The campaign and election were marked by a deadly crackdown by security forces on opposition supporters and an internet shutdown. In one week of protests in November, at least 54 people died. The government said opposition members and their supporters had been breaking public order laws and COVID-19 restrictions on gatherings. On Monday the government started to partially restore internet access. The United States and Britain have called for investigations into reports of fraud and other election issues. INCIDENT Wine called for the military to release him from house arrest, saying his home was not a legally recognised detention centre. He accused soldiers of assaulting his wife when she went into their garden. “The soldiers were pulling her by the breasts,” he said, adding that the incident was filmed on video and she would share it when social media services were restored. Military spokeswoman Brigadier Flavia Byekwaso said she was unaware of the incident. Slideshow ( 3 images ) The law gives petitioners 20 days after results are declared to challenge them in the Supreme Court. Wine said he wanted to meet with his party to decide on a strategy that could include peaceful protests. But the military has surrounded Wine’s home in Kampala since Thursday, saying it is for his own safety. Wine’s lawyers were denied access on Monday. One legislator for Wine’s party said he was beaten up by security forces when he tried to enter this weekend. The NUP’s Ssenyonyi said such attacks, including on the party’s polling agents, were being carried out to cripple the court challenge. At least 110 polling agents from Wine’s party have been arrested since the eve of the election. Some 223 suspects have been arrested during the election on offences that include assault, intimidation and voter bribery, police said.