London: Britain on Thursday banned the Indian Mujahideen (IM), making it a criminal offence to join and support the LeT-linked terror group which carried out "indiscriminate mass casualty attacks" in India and "posed a threat" to British nationals there.

MPs at the UK's House of Commons unanimously approved a motion on Wednesday night on proscribing IM and placing it on the list of 47 organisations that have been banned from functioning in UK.

"Indian Mujahideen is a terrorist organisation which has carried out a number of indiscriminate mass casualty attacks in India since 2007. It uses violence to achieve its stated objectives of establishing an Islamic state in India and implementing Sharia law," Home Secretary Theresa May said.

She added: "Proscribing Indian Mujahideen sends a clear message that we condemn its activities and enables the UK to demonstrate our commitment to counter-terrorism to our international partners."

The ban, which was slapped based on available evidence and information, came into effect on Thursday night.

Setting out the reasons for proscribing IM, Home Office Minister James Brokenshire told the House of Commons that the decision was "not taken lightly" but after thoroughly reviewing all the available information and evidence about IM. Brokenshire said IM "has frequently perpetrated attacks against civilian targets such as markets with the intention of maximising casualties... The organisation has also publicly threatened to attack British tourists, so they clearly pose a threat to British nationals in India."

Senior Labour leader Keith Vaz said: "I welcome yesterday's decision of the British Parliament to ban the Indian Mujahideen from operating in the UK. The international community should join together in criminalising this organisation, which has killed innocent civilians and uses violence indiscriminately."