Dozens of military officers, including some senior ones, have been arrested over an alleged plot to overthrow long-time President Yoweri Museveni, a Ugandan military official said Sunday.

More officers are being arrested over alleged acts of subversion following the detention Saturday of a colonel with the country’s air forces, military spokesman Lt. Col. Paddy Ankunda told The Associated Press.

Ankunda said the officers have suspected links to an opposition lawmaker, Michael Kabaziguruka, who is being questioned by the police over similar allegations.

Kabaziguruka is a close ally of opposition leader Kizza Besigye, who was charged with treason following a disputed presidential election in February. Besigye refused to accept the official results that gave victory to Museveni. Besigye claimed that he had won the election. Election observers said the polls were marred by many irregularities.