A German rapper turned jihadist nicknamed the “Goebbels of ISIS” has released a video calling on sleeper cells across Europe to carry out terrorist attacks, claiming “time is running out.” Scotland Yard has confirmed that it is reviewing security arrangements ahead of First World War commemorative events.

The two-and-a-half minute video released by Denis Cuspert, 39, on YouTube features staged scenes of jihadi sleeper agents preparing and detonating bombs in Times Square, New York, and carrying out attacks with knives. New footage of atrocities already carried out by Islamic state, including the murders of Jordanian pilot Moath al-Kasasbeh and British aid worker David Haines, as well as news footage from the attack on a Kosher supermarket in Paris in January, also appears.

Cuspert is heard rapping in German over the images, urging European jihadists to: “Fill your car with gas my brother hurry up. Your neighbour is a kafir slandering the messenger. Take a big knife and give him what he rightly deserves!

“Even while you are in Europe do your jihad. Allah is going to reward you, finish the dirty one. Paradise is waiting. Do it with sincerity.”

He also gloats at the failure of Western forces to send troops to Syria and Iraq, rapping: “To the enemies of Allah, where are your troops? We cannot wait. O Allah destroy them! Grant us victory over them. Take from us; make us honourable,” before chillingly warning “War has just begun. We have smelled blood. … We want your blood, it tastes so wonderful!”

Scenes of sniper rifles cut against those of public figures including President Obama suggest that political assassinations are also within the sights of western jihadists.

Five Australian teenagers, aged 18 and 19, were arrested in Melbourne this week, accused of plotting to use knives in a terrorist attack at events marking Anzac Day on April 25th, one of whom was charged last night. This year marks 100 years since allied troops landed on the Gallipoli peninsula.

A spokesman for Scotland Yard told the Sunday Times: “We already have protective security plans in place for major Anzac events in the UK but as a sensible precaution all forces have been asked to review security arrangements at related events.”

Cuspert, who now calls himself Abu Talha al-Amani, had a moderately successful career as a rapper under the name Deso Dogg (an abbreviation of “Devil’s Son), even touring with American rapper DMX, before converting to Islam whist in prison in Germany. Since travelling to Syria in 2012 he has built up a large following amongst British jihadists and supporters.

In February the US added Cuspert to its list of ‘global terrorists’, freezing all his assets under US control and prohibiting any transactions with him in the future, according to the Mail on Sunday.

The State Department said: “Cuspert is emblematic of the type of foreign recruit ISIL seeks for its ranks – individuals who have engaged in criminal activity in their home countries who then travel to Iraq and Syria to commit far worse crimes against the people of those countries.”

Meanwhile, foreign intelligence agents have admitted that there may be twice as many British jihadists on the battlefields of Syria and Iraq than previously estimated, about 500 of whom have returned to the UK.

In March, the Metropolitan police commissioner Bernard Hogan-Howe told the Commons home affairs committee that at least 700 Britons had travelled to Syria. But three “well-placed” foreign intelligence officials have told The Sunday Times: “We believe that even 1,600 is a very conservative estimate because by the time we started picking up on the scale of [the] problem, a lot of the people had slipped through the gates.

“And we’re still seeing at least about five people leaving the UK for Syria and Iraq every week – and that’s not to count the ones we don’t know about.”

Another added: “It is all about appearing to have control measures in place and to control public fear. It is not in the interest of the police to publicly discuss the exact extent of the numbers of British people who have gone to Syria and Iraq because they want to be able to manage people’s fears in relation to the growing problem. But they especially don’t want to be seen as having less control than they do have about stopping travelling jihadists.”