On Monday, the U.S. Department of State released a travel alert throughout Europe to warn US citizens about possible terrorist attacks that have been plaguing the continent for quite some time. The alert, which expires on September 1, 2017, is posted on the department's website for the public's perusal.

According to Travel Pulse, officials from the Department of State said the alert wasn't caused by any specific threat; rather, they just want to warn the citizens to exercise extra vigilance since the summer holidays are upcoming. For sure, the travel industry will see a higher growth of international over the summer, and many countries in Europe are popular tourist destinations.

"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," the alert said. "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."

The European alert also details the tactics and methods terrorists usually use during attacks. US citizens who have impending summer travels to Europe must especially exercise caution during their stay. It is imperative that they avoid shady places in Europe as well as suspicious people. Terrorists often use a variety of explosives and firearms to carry out attacks.

 It was also mentioned in the alert what kinds of places terrorists usually focus on. Generally populated destinations, shopping malls, and transportation hubs are usually the targets of these groups. Travelers must also be constantly wary of traveling in airports, places of worship, hotels and other places where large crowds are common. In these times, extra vigilance for safety must be constantly on point.