WASHINGTON: Alerting American citizens travelling to Europe to exercise caution and remain alert in the wake of the terrorist attack in Brussels that killed around 35 people, the US has warned of a near term terrorist attack in Europe."Terrorist groups continue to plan near-term attacks throughout Europe, targeting sporting events, tourist sites, restaurants, and transportation," the State Department said in a travel advisory on Tuesday.In its advisory, the State Department alerted US citizens to potential risks of travel to and throughout Europe following several terrorist attacks, including the March 22 attacks in Brussels that killed over 35 people which was later claimed by the dreaded Islamic State militant group.US citizens should exercise vigilance when in public places or using mass transportation."Be aware of immediate surroundings and avoid crowded places. Exercise particular caution during religious holidays and at large festivals or events," the State Department said.