Thailand’s military junta on Saturday dissolved the Senate, getting rid of one of the country’s remaining independent bodies after staging a coup d’état earlier this week.

The dissolution of the 150-parliamentarian Senate, half of whom were elected, was announced by National Peace and Order Maintaining Council (NPOMC) spokesman Colonel Winthai Suwaree on public television.

The disbanding of the Senate ended speculation that the Upper House might appoint the next Prime Minister.

Army chief General Prayuth Chan-ocha, who declared a coup d’état on Thursday, is now the acting Prime Minister and it is unclear whether he will appoint a civilian premier, as was the norm under past coups.

Since staging the coup, General Prayuth has summoned 190 politicians, activists and academics to report to authorities, detaining more than 100 of them.

“The military detention of senior politicians and civilians is very disturbing and I urge the NPOMC to immediately release them,” UN High Commissioner for Human Rights Navi Pillay said in Geneva.

Among those who have turned themselves in are former Prime Minister Niwattumrong Boonsongpaisan, who was ousted by the coup, and his predecessor Yingluck Shinawatra. Others detained at Army sites include leaders of both pro-government and anti-government protest movements such as Suthep Thaugsuban, who led seven months of demonstrations in Bangkok against the former government.

“Generally speaking we will detain them for about a week,” junta spokesman Colonel Werachon Sukhondhadhpatipak told a press conference on Saturday.

The Army has also arrested 21 alleged militants in north-eastern Thailand who were preparing to oppose the coup.