People are being warned to stay alert this week after an ISIS propaganda video called for attacks on New Year’s Eve celebrations.

In a seven-minute clip, an ISIS extremist tells his ‘brothers’ in English to ‘hunt down’ non-believers at clubs and churches this weekend.

A disturbing mock-up image then shows an explosion on the banks of the Thames in London during the annual New Year’s Eve fireworks party.

Tens of thousands of people go to the event every December 31, with around 250,000 expected to attend this Sunday, reports the Metro.

The video, reportedly released from Somalia, also showed a train derailing, as well as a car ploughing into a crowd of pedestrians.

It then calls on terrorists to attack nightclubs, churches and Christmas markets. The Foreign and Commonwealth Office has also warned people to be ‘vigilant’ while going to seasonal events across Europe.

‘There may be increased security in place over the Christmas and New Year period, including at Christmas markets and other major events that might attract large crowds,’ the warning, put in place for Germany, France, Switzerland and Sweden, says. ‘You should be vigilant and follow the advice of local authorities.’

Britain’s terror threat is currently ‘severe’, which means an attack is ‘highly likely’. The London Mayor’s Office, which is organising Sunday’s fireworks, said: ‘We encourage everyone coming to the event to be vigilant too, and to report anything of concern to a steward or police officer. At each entry point we will search all bags and check photo IDs of named ticket buyers.’