KAMPALA, Uganda (AP) — Ugandan police have detained the country's most prominent opposition leader over allegations of attempted murder following a deadly confrontation between police and opposition supporters in a remote town.

Four-time presidential candidate Kizza Besigye was being held in the capital, Kampala, following Wednesday's clashes, police spokesman Asan Kasingye said Friday.

"I have been informed that he is going to be charged with attempted murder," Kasingye said, giving no more details.

It was not possible to get a comment from Besigye.

Political tensions are rising in the East African nation over efforts by some lawmakers to extend the longtime president's rule.

The clashes erupted after police attempted to prevent hundreds of opposition supporters from accessing a stadium in Rukungiri, saying the rally was not authorized to take place. Besigye and other opposition leaders had been scheduled to speak there.

Kasingye confirmed one person was killed and several others injured, although Besigye's party said police shot dead two people.

Opposition leaders are trying to mobilize against efforts to remove an age barrier in the constitution that prevents 73-year-old President Yoweri Museveni from extending his rule when his current term expires in 2021.

The constitution bars anyone who is 75 or older from contesting the presidency.

Uganda's ruling party enjoys an overwhelming majority in the national assembly, and the bill to remove the age barrier is expected to pass.

The United States is urging Uganda's government to protect basic freedoms "without fear of intimidation," and Amnesty International says authorities "must end their absurd attempts to silence people opposed to scrapping the presidential age limit."

Museveni, a U.S. ally on regional security, took power by force in 1986 and was re-elected last year in a poll marred by allegations of fraud and voter intimidation.

There are no term limits in Uganda's constitution, one of the reasons that critics see the age limit as a measure against any attempts at a life presidency.

Uganda has not seen a peaceful transfer of power since independence from Britain in 1962.