Amnesty International on Monday denounced as "shocking" weekend clashes between security forces and royal guards in Uganda which left 62 dead, saying many victims appeared to have been executed.
The bloodshed, which took place in a traditional kingdom in the west, broke out when a joint patrol of police and troops was attacked by the royal guards in the town of Kasese.
The clashes continued into Sunday until police stormed the palace, arresting King Charles Wesley Mumbere of the Rwenzururu kingdom.
Speaking to the media on Monday, police spokesman Andrew Felix Kaweesi said the intial death toll of 55 had risen to 62, including 16 police officers and 46 royal guards.
The royal guards are believed to be part of a militia agitating for the creation of an independent republic straddling Uganda and the Democratic Republic of Congo.
Police said the king had been taken into custody in Kampala, with another spokesman telling NTV television that 139 royal guards had been arrested,
The violence drew a sharp reaction from the London-based rights watchdog, which said emerging evidence suggested some of the victims had been shot after their arrest.
"The full picture of the weekend’s events is yet to emerge, but there appears to be shocking examples of unlawful killings and a complete disregard for human rights during the arrests," said Abdullahi Halakhe, Amnesty International’s East Africa Researcher.
"In a shocking display of heavy-handedness, many people appear to have been summarily shot dead and their bodies dumped."