New Delhi: Britain has warned India about possible attack by ISIS and said all efforts must be taken to check activities of the Middle-East terrorist group. British officials have conveyed this to their Indian counterparts at the Indo-UK Counter Terrorism Joint Working Group meeting held in London on January 15-16.

Officials said that during the meeting, India had asked Britain to impress upon Pakistan not to differentiate between "good" and "bad" terrorists in the wake of recent attack on a school in Peshawar and said that it must take a firm stand on why Pakistan had become a nursery of terrorists.

"We have asked Britain to be alert about possible attack by Lashkar-e-Taiba there. Britain in turn has warned us that an attack by ISIS could take place in India," an official said.

Britain was more focused on the ISIS threat than from Pakistan-based terror groups.

"Britain is petrified that a terror attack can take place on its soil by ISIS and radical elements associated with it may help the group," the official said.

British security agencies have good links with Pakistani intelligence agency ISI and they feel that it is an insurance for preventing a terror attack on its soil by Pakistan-based terror groups, the official said.

Four Mumbai youth had disappeared in Iraq-Syria in May 2014 and apparently joined ISIS. One of them returned in November last year and was subsequently arrested.

A Bangalore-based executive was also arrested last month for operating a pro-ISIS Twitter handle to propagate the ideology of the Middle-East terrorist group. A US-returned engineer, on way to join ISIS, arrested in Hyderabad two days ago.

Asif Ibrahim, who had retired as Director of Intelligence Bureau on December 31, 2014, had said in November last that there was an imminent danger of Indian youths moving to the conflict zone (Iraq-Syria), emerging as a role model and such developments may directly or indirectly pose a threat to the country.

The Indian delegation to the London meeting also raised the issue of growth of Sikh radicalisation in Britain and asked for action.

"There are 2-3 TV channels in the UK which are carrying offensive material against India and encouraging Sikh radicalisation. We have asked the UK to crack down on them and impressed upon them that Sikh radicalisation is dead in India but still has a presence in the UK," the official said.

Indian officials also highlighted the issue of regular fund flow from Britain to the families in India of jailed Sikh terrorists.

There are 7 lakh Sikhs and 10 lakh Pakistanis based in the UK and Indian officials got the impression that British officials have been soft towards Sikh radicals and anti-India Pakistani elements as they have turned into significant vote banks as well, they said.

During the meeting, both countries have agreed on training of its special forces and an agreement on civil aviation security, officials said.