Hundreds of protesters tried to break through police road blocks
Dozens of people in Malaysia have been arrested for taking part in opposition-led protests over who controls the parliament in the state of Perak.
Police were deployed outside the state legislature, while inside ministers scuffled and shouted at each other.
The state has become the focus of a power struggle between Malaysia's ruling party and the main opposition.
The opposition lost its majority when three legislators defected to become independents earlier this year.
The Sultan of Perak fired the alliance's administration and asked the National Front to govern, but there is still no real agreement over who is in charge.
The high court will decide on the legitimacy of the new state government next week.
The wrangling in Malaysia's second largest state has been going on for months.
Perak was one of five states that voted for the opposition in the March 2008 elections, in which the ruling party lost its two-thirds majority for the first time since the country's independence from Britain in 1957.
But earlier this year, three state legislators defected to become independents, tipping the balance in favour of the governing National Front coalition.
Thursday's violence happened as the National Front was holding its first parliamentary session since ousting its rivals.
Activists broke through police lines, and the speaker of the assembly, who oversees proceedings, was surrounded and forced from the chamber by plain-clothes police officers.
He had refused to stand aside after a pro-government member was chosen to replace him.
According to the BBC's Robin Brant in Kuala Lumpur, this is the first time in Malaysia's history that police have intervened in parliamentary proceedings.
There were no violent clashes but dozens of protestors were arrested, including several opposition members.
The opposition is campaigning for fresh state elections.
Najib Razak - who became the head of the ruling party and Malaysia's prime minister last month - was seen as playing a prominent role in the power struggle.