Visitors to Arlington National Cemetery in Virginia will need to present an ID, as the landmark increases its security. Effective immediately, visitors who are 16 and older must show a valid state- or government-issued photo ID when entering the cemetery. Visitors who are 16 or 17 years old may use a school-issued ID. Whether you are attending a funeral, part of a tour group, on a school trip or a personnel on official business, you will need to show an ID. This includes pedestrians, drivers and passengers. The cemetery asked visitors to be patient, as this will add time to their travel. “Physical security is everyone’s responsibility,” the cemetery said in a statement.

Effective immediately, all visitors 16 years and older (pedestrians, drivers and passengers) must present a valid state or government issued photo identification upon entering the cemetery. Visitors include all funeral attendees, tourists, and personnel on official business. 2/

— Arlington National Cemetery (@ArlingtonNatl) January 3, 2020

The military cemetery, which is under the U.S. Army, said the change is due to “current conditions.” It did not specify what these current conditions were. The U.S. Park Police said it is stepping up patrols and vigilance at landmarks in three major American metropolitan areas as a result of mounting tensions with Iran, The Associated Press reported. A U.S. Park Police spokesman told The Associated Press the agency will have increased visibility and vigilance at different icons, though he declined to specify which ones. U.S. Park Police is responsible for protecting several attractions in D.C., including the Washington Monument and the Lincoln and Jefferson memorials. D.C. Mayor Muriel Bowser said the city, its police department and the Department of Homeland Security “will remain in close contact with regional and federal partners to monitor evolving events — both at home and abroad.” In the wake of the U.S. airstrike near Baghdad’s airport that killed the head of Iran’s elite Quds Force, cities across the U.S. have increased security despite reassurances there are no specific or credible threats against each location. The Los Angeles Police Department said that it is monitoring events developing in Iran. Police in Boston said they are monitoring events around the world. As an added precautionary measure, Chicago has increased security presence at its airports. And New York City Mayor Bill de Blasio said that there will be heightened security at locations around the city. The Associated Press contributed to this report.