Several people wearing black, the colour chosen by the opposition to protest against the takeover, were arrested.
Jenice Lee, an opposition state assemblywoman from the state of Selangor near the capital Kuala Lumpur was among those detained.
"I am an elected representative, I am not fighting you," she said as she was dragged away.
Lim Kit Siang, a senior member of the national parliament with the opposition Democratic Action Party, was also barred from entering the assembly building.
He said the government's move had turned the area around the assembly into a "war zone" and said the refusal to allow protests was "a national and international disgrace".
|Wong Chin Huat, an activist, was arrested on Tuesday amid rising political tensions
The protests are the latest stage in a stand-off between the ruling coalition and the opposition, which last year scored its best ever result in national elections, taking control of five state governments.
In February however, in a move led by Najib Razak, Malaysia's recently-installed prime minister, three opposition politicians in the Perak assembly were convinced to switch their allegiance to sit as independents.
That deprived the People's Alliance coalition of its majority in the state.
In the run-up to the protests in Ipoh, police arrested a further 19 people, including a politician from the country's Islamist opposition and a voting reform activist.
Mohamad Sabu, the vice president of the Pan Malaysian Islamic party (PAS), was arrested in Kuala Lumpur in a move that a police spokesman said was linked to the situation in Perak where he was due to lead prayers on Thursday.
On Tuesday, Wong Chin Huat a voting reform activist was arrested and charged with sedition after he urged Malaysians to wear black to protest the Perak takeover.
He faces up to three years in jail if convicted.
The spate of arrests have raised concerns among opposition leaders of a crackdown against critics of the government.
Najib, who took office on April 3, came to power promising to "uphold civil liberties" and demonstrate "regard for the fundamental rights of the people of Malaysia".
But Anwar Ibrahim, the head of Malaysia's opposition, said that despite Najib's "rhetoric of tolerance" the arrests showed the prime minister was "bent on using tough, draconian measures".
"That the campaign for people to wear black can be deemed as seditious and a threat to national security, this is ridiculous," he told Reuters ahead of Thursday's protests.
Anwar, a former deputy prime minister is to stand trial in July for sodomy, charges he says are politically motivated.
The former deputy prime minister-turned opposition figurehead was imprisoned on corruption and sodomy charges in the late 1990s, although the sodomy conviction was later overturned.