The creation of a drone wall in Europe is likely to be central to talks among European leaders this week, following a spate of incursions into the region’s airspace and increasing concerns over the security threat they pose.

Poland, Estonia and Romania — countries on Europe’s northern and eastern flank and close to Russia — have all reported airspace incursions involving either Russian jets or drones recently.

Norway, Denmark and Germany have also reported incidents involving unidentified drones in their airspace in last week, causing disruption to airports and air traffic.

Russia denies it’s behind drone provocations against its European neighbors, describing them as “unfounded accusations.”

Drones targeted Danish airports last week, causing widespread disruption, and Unmanned Aerial Vehicles (UAVs) were spotted near military sites last weekend. The government said the disruption was the work of a “professional actor” but had no evidence of Russian involvement.