NATO is launching a new military campaign in Poland following an incursion by Russian drones in Polish airspace earlier in the week, the military alliance confirmed in a statement.

The incursion into Poland deepened longstanding fears that the three-year war between Poland’s neighbors could precipitate a wider conflict.

A restricted zone in the eastern part of the NATO country is in place following Russian drones entering its airspace.

Poland's two presidential candidates held their last election campaigns on Friday ahead of a runoff on Sunday.

WARSAW, Sept 13 (Reuters) - Polish and allied aircraft were deployed to protect Polish airspace on Saturday because of a threat of drone strikes in neighbouring Ukraine, and the airport in the eastern Polish city of Lublin was closed, Polish authorities said.

Polish Prime Minister Donald Tusk on Wednesday said his country is the closest to open conflict since World War II, according to multiple reports, likely referring to Russian drones that breached Poland’s airspace overnight.

Denmark, France and Germany have joined a new mission to bolster the military alliance's eastern flank after Russian drones flew into Poland on Wednesday.

Poland's Bartosz Zmarzlik clinched a record-equalling sixth Speedway GP world championship title on Saturday in Vojens, Denmark, becoming the first rider in history to win four successive gold medals in the sport.