State Department is warning Americans living in and traveling to Europe of the ongoing threat of terrorist attacks on the continent through the summer.

In a new travel alert issued on Monday, the department said the Islamic State group, al-Qaida and their affiliates retain the “ability and to plan and execute” attacks in Europe. It said the U.S. officials remain concerned about the potential for future attacks, following a series of strikes in France, Russia, Sweden and Britain.

The alert said U.S. citizens should be especially vigilant at large, high profile events, particularly during the summer travel season.

The department’s last terror alert for Europe was issued on November 21 last year and expired on February 20.

Monday’s alert expires on September 1.

This article was written by Matthew Lee from The Associated Press and was legally licensed through the NewsCred publisher network. Please direct all licensing questions to legal@newscred.com.

Following is the text of the Europe Travel Alert:

The Department of State alerts U.S. citizens to the continued threat of terrorist attacks throughout Europe. This Travel Alert expires on September 1, 2017.

Recent, widely-reported incidents in France, Russia, Sweden, and the United Kingdom demonstrate that the Islamic State of Iraq and ash-Sham (ISIS or Da’esh), al-Qa’ida, and their affiliates have the ability to plan and execute terrorist attacks in Europe. While local governments continue counterterrorism operations, the Department nevertheless remains concerned about the potential for future terrorist attacks. U.S. citizens should always be alert to the possibility that terrorist sympathizers or self-radicalized extremists may conduct attacks with little or no warning.

Extremists continue to focus on tourist locations, transportation hubs, markets/shopping malls, and local government facilities as viable targets. In addition, hotels, clubs, restaurants, places of worship, parks, high-profile events, educational institutions, airports, and other soft targets remain priority locations for possible attacks. U.S. citizens should exercise additional vigilance in these and similar locations, in particular during the upcoming summer travel season when large crowds may be common.

Terrorists persist in employing a variety of tactics, including firearms, explosives, using vehicles as ramming devices, and sharp-edged weapons that are difficult to detect prior to an attack.

If you are traveling between countries in Europe, please check the website of the U.S. embassy or consulate in your destination city for any recent security messages. Review security information from local officials, who are responsible for the safety and security of all visitors to their host country. U.S. citizens should also:

Follow the instructions of local authorities. Monitor media and local information sources and factor updated information into personal travel plans and activities.

Be prepared for additional security screening and unexpected disruptions.

Stay in touch with your family members and ensure they know how to reach you in the event of an emergency.

Have an emergency plan of action ready.

Register in our Smart Traveler Enrollment Program (STEP).

We continue to work closely with our European partners and allies on the threat from international terrorism. Information is routinely shared between the United States and our key partners to disrupt terrorist plotting, identify and take action against potential operatives, and strengthen our defenses against potential threats.

Photo Credit: The U.S. State Department issued a new warning about European travel. Pictured, police officers check supporters before the French League One soccer match between Paris Saint Germain and Troyes, at the Parc des Princes stadium in Paris Nov. 28, 2015. Christophe Ena / Associated Press