Security measures have been heightened in Islamabad, the capital of Pakistan, with some shops closed and traffic partially restricted. Police presence has been reinforced around several hotels. According to Pakistani sources, three aircraft carrying U.S. personnel landed at the Nur Khan Air Base that day. Currently, shops along the roads connecting Islamabad and the Nur Khan Air Base have been shut down, and security forces, including military and police, have been deployed around several major hotels in the city. Meanwhile, the Serena Hotel, where the previous round of U.S.-Iran negotiations took place, and the nearby Marriott Hotel have notified guests to check out on the same day. (Xinhua)