German authorities will deploy around 5,000 police officers to safeguard the Munich Security Conference this week, bolstered by reinforcements from neighboring countries.

Officials announced Wednesday that the international gathering will draw more than 60 heads of state and government, alongside about 100 foreign and defense ministers, among over 1,000 delegates representing 120 nations.

Security measures will be extensive. Airspace above Munich will be closed to aircraft and drones during the event, which runs from Friday to Sunday. U.S. Secretary of State Marco Rubio and roughly 50 members of the U.S. Congress are expected to attend.

Deputy police chief Christian Huber described the operation as “international,” with support from France, Austria, Switzerland, and the Netherlands. German police resources are stretched due to nationwide carnival festivities, making foreign reinforcements essential.

Authorities anticipate 21 demonstrations during the conference, including two rallies against Iran’s government. A large protest against Tehran is expected Saturday, with participants traveling from across Europe. Opponents of the conference itself have also registered a demonstration that could draw up to 4,000 people.