Deputy Prime Minister Datuk Seri Zahid Hamidi has dismissed accusations of unfairness in the crackdown in connection with the yellow-shirt Bersih protest rally on Saturday.
"Why is this an abuse of power? We did not only haul up people from one rally. We also detained many of the Red Shirts members," said Datuk Seri Zahid.
He said the arrests were to demonstrate to people that the country's laws should be respected.
Just hours after the home minister's remarks, more arrests took place, including two senior opposition MPs, Mr Tian Chua and Ms Zuraida Kamaruddin, who were picked up just before midnight.
At least 22 people have been detained - 15 critics of Prime Minister Najib Razak and his government, and six members of the pro-government Red Shirts movement, including their leader, Umno divisional chief Jamal Yunos.
Eight of those nabbed on Friday were released yesterday, according to news reports.
Ms Maria Chin Abdullah, the head of the reformist Bersih movement, has been remanded for 28 days under the Security Offences (Special Measures) Act, the law that was adopted in 2012 after the Internal Security Act (ISA) was repealed. Bersih said yesterday that it would file a legal challenge against their chief's remand order.
Ms Chin's lawyer R. Sivarasa said she was being held in solitary confinement at an undisclosed location.
"She has been placed in a cell with no windows and only lights for 24 hours. If you ask me, those are tortuous conditions by international standards," he said.
Mr Eric Paulsen, another lawyer for the Bersih chief, who is also co-founder of rights organisation Lawyers for Liberty, said police had been "extremely reckless in accusing Bersih participants, activists and even MPs for rioting when the event ended peacefully".
Human Rights Watch's deputy Asia director Phil Robertson echoed his view.
"These wild claims by police, manifested now in charges of undermining parliamentary democracy or rioting, point to a clear government agenda of vilification of activists without regard to facts.
"The government's decision to arbitrarily use anti-terror legislation against Bersih chair Maria Chin Abdullah is a particularly chilling development that really threatens to undermine rule of law in Malaysia," Mr Robertson told The Straits Times.
Prime Minister Najib, however, criticised the Bersih gathering, denouncing it as "illegitimate".
"If we want to topple the government, this is not a legitimate way. If not, the country will be in chaos and the people will suffer," he was quoted as saying by the New Straits Times.
State news agency Bernama also quoted the Prime Minister, who is in Peru for the Asia-Pacific Economic Cooperation leaders' meeting, as saying that Malaysians were fed up of Bersih.
He slammed former premier Mahathir Mohamad for not practising what he used to preach when in power for 22 years until 2003. Tun Dr Mahathir, who was staunchly against street protests while in power, took to the streets on Saturday to call for Malaysians to reject Mr Najib's government.
Compared to the Bersih 4 rally last year, which was dominated by Chinese Malaysians, the crowd this year was more multiracial.
According to Kuala Lumpur police, 15,500 people turned up for Bersih 5, although local media reports put the figure at more than double that. Last year's Bersih protest attracted about 50,000 people.
The Red Shirts, for their part, managed to muster only 2,500 supporters on Saturday.