The United States has criticised the handling of Uganda's disputed presidential election and raised concerns about the house arrest of an opposition leader who failed to end President Yoweri Museveni's 30-year rule.
Museveni, one of Africa's longest serving leaders and a U.S. ally, was declared winner on Saturday but opponents rejected the outcome of the election. European Union and Commonwealth observers have also criticised the handling of Thursday's poll.
Main opposition candidate Kizza Besigye was arrested three times this week and alleges the police have put him under house arrest and blocked his electronic communication. Besigye has described the election as a sham and another challenger, Amama Mbabazi, said the poll was "fundamentally flawed".
The U.S. State Department said it was concerned by Besigye's continued house arrest and the shuttering of social media in Uganda, where Facebook, Twitter and WhatsApp have faced outages since election day.
"We call for his immediate release and the restoration of access to all social media sites," Mark Toner, U.S. State Department deputy spokesperson, said late on Saturday.
He said the widespread reports of irregularities and the conduct of officials was "deeply inconsistent with international standards and expectations for any democratic process".
Ugandan deputy government spokesman, Shaban Bantariza, dismissed the U.S. criticism, saying it "appears partisan and lacks merit".
He added: "The few and isolated irregularities that occurred can not be used to discredit the integrity of an exercise that otherwise went smoothly."
The EU observer mission said the election had been conducted in an "intimidating" atmosphere, while Commonwealth observers said the poll "fell short of meeting some key democratic benchmarks".
Museveni, 71, has presided over strong economic growth but is accused at home and abroad of repression of dissent and failing to tackle rampant corruption in the nation of 37 million people.
Besigye has urged the international community to denounce the poll win by Museveni, who has won favour with the West by sending Ugandan troops to Somalia to battle Islamist militants with ties to al Qaeda.
U.S. Secretary of State John Kerry called Museveni on Friday to voice concern over Besigye's detention, the harassment of opposition figures and the shutdown of social media.
"I told Kerry not to worry a lot about the internal affairs of Uganda because we know how to handle the issues," the Daily Monitor newspaper on Saturday quoted the president as saying.