Thiruvananthapuram, March 13 (IANS): Kerala Chief Minister Oommen Chandy on Friday described as "a black day" the violence that rocked the state assembly.

"Our assembly has witnessed lot of friction earlier when the rival fronts have lost their temper. But what happened today has never been witnessed in the history of our assembly," he told the media.

"Our speaker (N. Sakthan) was prevented from addressing and his podium was ransacked and destroyed by opposition legislators. This is a black day in the history of the Kerala assembly," he said.

The assembly witnessed unruly scenes as members of the Left broke the speaker's chair and electronic equipment to register their protest against Finance Minister K.M. Mani, who they did not want to present the budget.

The finance minister had to be escorted by the ruling United Democratic Front and a huge battery of Watch and Ward Staff so that he could read out the budget.

Trouble had been brewing since Thursday afternoon when all the Left legislators stayed back for the night to ensure that Mani was not allowed to enter the assembly.

They have been accusing him of taking a bribe of Rs.1 crore to reopen the closed down bars in the state and have demanded his resignation.

Mani chose to remain in the assembly Thursday night.

Sakthan told reporters that he was deeply saddened over what had happened.

"We tried our best to tell the Left (to have a) democratic form of protest but they crossed all levels of (toleration)," he said. "Such a thing has never ever happened in the assembly."

Marxist leader and former chief minister V.S. Achuthanandan said close to 20 Left legislators have been roughed up by the security staff of the assembly and many were receiving medical care.