Minsk, Sep 7 (IANS): At least 633 people were arrested in Belarus following a fourth consecutive weekend of protests against President Alexander Lukashenko, the Interior Ministry said on Monday.

In a statement, the Ministry also said that some 363 people had been sent to detention centres pending court hearings, reports the BBC.

In the protests held on Sunday, thousands more defied heavy security and rallied in the capital Minsk, where troops and water cannon were deployed.

Witnessed have told the media that the police began to make arrests in Minsk after the unsanctioned rally ended and people were going home.

Video footage on Sunday shows men in plain clothes beating peaceful protesters with batons.

But Internal Affairs Minister Yuri Karayev defended the actions of the security forces.

"They talk about the brutality of the Belarusian police, and I want to say this: there are no more humane, restrained and cool-headed police anywhere in the world," the BBC quoted the Minister as saying to the official Belta news agency.

Sunday has become the key day for street demonstrations since the rallies began after Lukashenko, who has been in power since 1994, won a sixth term in the August 9 elections.

According to official results, he won more than 80 per cent of the votes and opposition leader Svetlana Tikhanovskaya garnered only 10 per cent.

Mass unrest since then has seen at least four people killed and hundreds injured.

A number of opposition figures have fled the country.

On September 5, activist Olga Kovalkova became the latest to say she had taken refuge in neighbouring Poland amid threats of imprisonment.

A day earlier, Tikhanovskaya, who has sought refuge in Lithuania, urged the UN to help halt the authorities' crackdown on protesters.