WARSAW — Poland and Latvia imposed sweeping restrictions on civilian flights along their eastern borders after Russian drones crossed into Polish airspace in the early hours of Wednesday.

The Polish restrictions went into effect at 10 p.m. on Wednesday, covering a zone running along the border with Ukraine and Belarus. They will remain in place until midnight Dec. 9, the maximum one-time extent allowed by regulations. PANSA, the Polish air traffic agency, laid out the new rules in a statement.

The Latvian restrictions go into effect on Thursday at 6 p.m. in a zone along the country’s borders with Russia and Belarus and will remain into effect at least until Sept. 18, with the possibility of extension, the government said.

In the Polish zone, only military aircraft are permitted in the zone from sunset to sunrise. During daylight hours, flights will be allowed only if they meet strict conditions such as filing a flight plan, carrying active transponders and maintaining constant radio communication with air traffic control. 

Military jets on quick reaction alerts, known by the NATO call signs GARDA or ALPHA SCRAMBLE, will be authorized to operate. 

Civilian drones are banned at all times, PANSA also specified.

Exemptions include flights with official status, including HEAD for heads of state, STATE for government missions, SAR for search and rescue, HOSP and MEDEVAC for medical evacuations, and FFR for firefighting response. 

Flights not meeting the listed requirements may still be authorized if they involve state aviation or air ambulances, if they are carried out to protect human or animal life and health in cases such as natural disasters, accidents, ecological threats or other emergencies, or if they are linked to the protection and monitoring of critical infrastructure.

In Latvia, Defense Minister Andris Sprūds said the measure will allow the country to better control the restricted airspace, make it easier to detect threats and free up the area for NATO’s Baltic Air Policing mission.

“Russian unmanned aerial vehicles in NATO airspace are a warning signal, and we must do everything possible to prevent an escalation of drone attacks,” Sprūds said.

Ukrainian President Volodymyr Zelenskyy said Ukraine was ready to help with efforts to combat Russian drone incursions. 

“We are ready to provide technology, crew training, and necessary intelligence data …  Ukraine proposes to defend airspace in a coordinated, thoughtful and joint manner,” Zelenskyy said in a statement published on social media. 

Laura Kayali contributed to this report.