The U.S. State Department issued an advisory for Americans traveling to Europe warning them of potential terrorist attacks — mainly during the holiday season. Countries like Belgium, France, Germany and Turkey had fallen prey to such attacks this year but the department warned that likely assaults may take place throughout Europe.

“Credible information indicates the Islamic State of Iraq and the Levant (ISIL or Daesh), al Qaeda, and their affiliates continue to plan terrorist attacks in Europe, with a focus on the upcoming holiday season and associated events. U.S. citizens should also be alert to the possibility that extremist sympathizers or self-radicalized extremists may conduct attacks during this period with little or no warning. Terrorists may employ a wide variety of tactics, using both conventional and non-conventional weapons and targeting both official and private interests,” the advisory read.

The department also advised Americans to exercise caution during holiday festivals and events and at outdoor markets, popular tourist spots, public transport, restaurants and places of worship.

“European authorities continue to conduct raids and disrupt terror plots. We continue to work closely with our European allies on the threat from international terrorism,” the advisory noted.

The travel advisory will remain in place until Feb. 20, 2017, according to the State Department.

Similar alert by the department was issued in May stating that the high number of tourists in Europe during summer could potentially raise the risk of terror attacks in public places such as “major events, tourist sites, restaurants, commercial centers and transportation.”