According to reports in the Mirror, militants are likely to target Queen Elizabeth during the VJ commemorations, scheduled to be held in London on Saturday. Thousands of people are expected to gather for the event on this weekend.
The report also claimed that there are seven ISIS terrorists are in UK to carry out the attack.
The militants are allegedly planning to explode a "pressure cooker bomb" in central London during events to mark 70 years since the end of the Second World War.
ISIS known for their brutality, recently released a sickening video showing their new way of execution technique - forcing men to kneel on explosives and then blowing them up.
A group of 10 men are then led by the black-clad terrorists to the site and forced onto their knees.
The killers then flee the site and detonate the explosives, killing the victims in a huge blast.
Buckingham Palace officials refrained themselves from commenting on the reported threat.
The Queen and members of the Royal Family will take part in a series of events on Saturday.