Government travel information for people planning Christmas market breaks across seven European countries has been altered to reflect heightened security.
The revised Foreign and Commonwealth Office advice covers Austria, Belgium, France, Germany, Holland, Italy and Denmark.
“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 FCO said.
“You should remain vigilant and follow the advice of local authorities.”
The updated travel advisory comes a week after the US State Department issued a warning to American travellers of an increased risk of terrorist attacks throughout Europe this winter.
It urged US citizens to “exercise caution” at Christmas holiday festivals, events and outdoor markets.