The British government on Thursday banned the Indian Mujahideen (IM) describing it as a threat to national security and citing its alleged involvement in several terror attacks, including the Mumbai bombings.

The ban, which followed a unanimous vote in the House of Commons, came as five men and a woman were arrested in London in a counter-terror swoop ahead of the Olympic Games. Police said the arrests though “significant” were not linked to any imminent attack. Those arrested — three brothers and a married couple — were aged between 18 and 30. The BBC said some were British nationals.

Announcing the ban, Home Office Minister James Brokenshire said that there was evidence that the IM had been “engaged in indiscriminate mass casualty attacks in India.”

“For example, in May 2008, a spate of bomb detonations in the city of Jaipur killed 63 and in September of last year an explosion outside the high court in Delhi reportedly killed 12 and injured 65,” he said.

“We believe that there is ample evidence that IM is concerned in terrorism and I believe it is right that we add the organisation to the list of proscribed organisations,” the Minister told MPs.

The ban makes it an offence to be a member of the IM under Britain’s Terrorism Act 2000. The group is already banned in several countries, including the U.S. and New Zealand.

Mr. Brokenshire said that IM “has frequently perpetrated attacks against civilian targets… with the intention of maximising casualties.”

“They use violence to achieve their stated objectives of creating an Islamic state in India and implementing Sharia law,” he said. “IM has sought to incite sectarian hatred in India by deliberately targeting Hindu places of worship, such as a prayer ceremony in Varanasi which killed a child in December 2010.

“The organisation has also publicly threatened to attack British tourists, so they clearly pose a threat to British nationals in India,” Mr. Brokenshire said.

Welcoming the move, Labour’s shadow home office minister Diana Johnson said the IM was behind “some of the most appalling acts of terrorism in recent years.”