Ottawa is advising Canadians travelling to the U.K. ahead of the coronation of King Charles III to exercise a 'high degree' of caution due to the threat of terrorism.

With large crowds expected to gather in London for King Charles III's coronation on Saturday, the travel advisory cites “a threat of terrorism in Europe” and warns Canadians that “further attacks in the United Kingdom are likely.”

The advisory notes London is a frequent target, but attacks could occur elsewhere.

"In the United Kingdom, previous incidents have resulted in casualties. They include random violent incidents in public areas, such as knife and vehicle attacks as well as explosions.“

Several recent terrorist attacks in London have targeted public spaces popular with tourists. In 2019, a man wearing a fake explosive vest fatally stabbed two people on the busy pedestrian and vehicle London Bridge. A similar attack in 2017 on the Westminster bridge left five people dead and 40 others wounded.

Islamic extremists were responsible for the 2017 van attack on a crowd of people outside a London mosque, that left one dead and 11 injured. Also in 2017, an explosion at a crowded subway station during rush hour injured 29 people.

Aside from the threat of terrorism, Canadians are advised to expect delays and disruptions while visiting the U.K. during the days leading up to the coronation and after, especially in the vicinity of Buckingham Palace and Westminster Abbey.