KAMPALA (Reuters) - European Union diplomats in Uganda on Friday deplored “brutal treatment” of lawmakers arrested over a stoning of President Yoweri Museveni’s convoy, and a rights body called for Ugandan authorities to prosecute the perpetrators of the alleged abuses.

Government spokesman Ofwono Opondo denied security personnel had deliberately beaten up the lawmakers and others. “Some of these injuries could have been sustained in the course of the (convoy) confrontation,” he said.

Five lawmakers critical of Museveni were detained this week after supporters of an independent candidate participating in a parliamentary by-election threw stones at a passing presidential convoy. One person was shot dead in the incident.

On Thursday four of the detained lawmakers alongside dozens of others were charged with treason and unlawful possession of weapons and ammunition. Three of the detained lawmakers took part in the stoning, according to the charge sheet.

Opposition politicians and the defendants’ lawyer have said the detained MPs and their co-accused were tortured during their arrest and detention.

“The reported brutal treatment of elected members of the Uganda parliament, journalists and civilians, as well as the loss of human life, are very disquieting events,” the Kampala-based EU diplomats said in a joint statement.

“There is no room for repression nor violence in a modern democratic Uganda,” said the statement, also signed by ambassadors of non-EU Norway and Iceland.

In power since 1986, Museveni has been accused by critics of using security forces to stifle opposition through intimidation, beatings, detentions and prosecutions on trumped-up charges.

His supporters say he has held power for so long in the East African country because of genuine mass support.

Museveni has enjoyed Western support for having contributed to the fight against militant Islam, particularly through the Ugandan role in an African peacekeeping force in Somalia that has tackled al Shabaab jihadists.

POPULAR MUSICIAN AMONG THE ARRESTED

On Thursday, two lawyers who attended a military court session where one of the MPs, Robert Kyagulanyi, was brought in to be charged said he was unable to talk or walk, bore visible injuries and was not aware of his surroundings.

Security agents barred other people, including Kyagulanyi’s wife and relatives, from attending the hearing.

Kyagulanyi, a popular musician known by his stage name Bobi Wine, was first elected to parliament last year. He has since amassed a large following among youth electrified by his scathing criticism of Museveni sometimes delivered in his songs.

On Thursday, dozens of youths staged a protest in a suburb of the capital Kampala where Kyagulanyi has a recording studio. A police spokesman said 12 demonstrators had been arrested.

Images have also emerged on social media of Francis Zaake, another detained member of parliament, lying on a bed, eyes closed, his face swollen and with wounds on his palm.

“If Kyagulanyi or any of the others arrested in Arua is in the condition his lawyers described, and prosecutors do not urgently work to bring torture charges against those accountable, it will make a mockery of Uganda’s constitutional provisions against torture...,” said Maria Burnett, associate Africa director for New York-based Human Rights Watch.