India's parliament has witnessed heated protests after 49 more opposition MPs were suspended, taking the total number of barred lawmakers to 141.

The MPs were protesting against last week's security breach in parliament.

On Monday, the opposition accused Prime Minister Narendra Modi's government of attacking democracy after a record 78 MPs were suspended in one day.

Most of the lawmakers have been barred for the rest of the winter session, which ends on Friday.

But around two dozen of them may have to stay away for longer, depending on the decision of the parliament's privileges committee.

Most of the suspended MPs are part of the INDIA alliance, a coalition of opposition parties that hopes to take on Mr Modi's Bharatiya Janata Party (BJP) in next year's general election.

The alliance has 142 MPs in the 543-member Lok Sabha - the lower house of parliament - of which 95 have now been suspended. It has 101 MPs in the 250-member upper house or Rajya Sabha (a few seats are vacant) - of these, 46 have been suspended.

"Unfortunately, we have to start writing obituaries for parliamentary democracy in India," Congress MP Shashi Tharoor said on Tuesday after being suspended.

The governing BJP has accused the opposition leaders of deliberately disrupting parliament proceedings.

The developments are expected to worsen already frosty relations between the opposition and Mr Modi's government.

Many opposition MPs had been demanding a statement in parliament from either federal Home Minister Amit Shah or Mr Modi on last week's security breach - two people entered parliament and set off coloured gas and shouted slogans, while two others protested outside parliament.

Six people have been arrested so far in the case, with police charging the four protesters under a stringent anti-terror law.

Police have not officially disclosed a motive, but media reports and the families of the accused have said the protesters were unemployed and wanted to express their frustration with the government's policies.

The breach occurred on the 22nd anniversary of a deadly militant attack on the parliament.

Opposition MPs have also asked for a discussion in parliament on the security lapse.

Though Mr Modi did not speak in parliament on the issue, he told a Hindi newspaper that "what happened is very serious".

"There is no need to debate this, there should be a detailed investigation into this," he told the Dainik Jagran newspaper.

Mr Shah has also not spoken in parliament, but said at an event that a high-level enquiry had been ordered into the incident and accused the opposition of politicising the security breach.

"PM can give an interview to a newspaper, home minister can give interviews to TV channels," said Mallikarjun Kharge, president of the opposition Congress party. "But they have zero accountability left to parliament, which represents the people of India." Mr Kharge, a member of the Rajya Sabha, has not been suspended yet.

Manoj Kumar Jha, an MP from the regional Rashtriya Janata Dal, called his suspension "a badge of honour".

"It's a recognition that they are trying to suppress the questions we [opposition] are raising," he told reporters on Monday.

Some opposition MPs including Mr Kharge have alleged that the government has deliberately suspended many opposition leaders to pass important bills without debate.

But federal minister Piyush Goyal, who on Monday moved a motion to suspend 34 MPs in the upper house, called the opposition's protest a "pre-planned strategy" to disrupt the functioning of parliament and block important bills.

He also accused opposition MPs of disrespecting the parliament and insulting the Lok Sabha speaker and Rajya Sabha chairman by refusing to heed their requests to not bring protest signs to the well of the house.