WARSAW, Poland - A Russian missile passed through Polish airspace Friday, entering from and then back into Ukraine, the Polish army said, as Russia pummeled Ukraine with one of the biggest air attacks of the war.

Firefighters extinguish a fire in a high-rise building after a missile attack in Odesa on December 29, 2023, amid the Russian invasion of Ukraine. Russia launched drone and missile strikes across Ukraine on December 29, 2023, killing at least 12 people and wounding over 70 in one of the biggest air attacks of the war. (Photo by Oleksandr GIMANOV and Oleksandr GIMANOV / AFP)

"Everything indicates that a Russian missile entered Polish airspace... It also left our airspace," said General Wieslaw Kukula, chief of the general staff of the Polish armed forces.

"We have national and allied radar confirmation," he told reporters.

The missile was in Polish airspace for three minutes, said Maciej Klisz, operational commander of the Polish army.

"We sent our forces, fighter jets, to intercept it and shoot it down if necessary but the duration and the flight path... made this impossible and allowed the missile to leave Polish territory," Klisz said.

Klisz said Poland's air defense system had been put on alert because of a wave of Russian drone and missile strikes on Ukraine.

The army said it had also carried out a ground search in the place where the signal from the missile was lost.

Polish civilian and military authorities have held emergency meetings and Polish President Andrzej Duda has spoken to NATO chief Jens Stoltenberg following the incident, who reacted on social media.

"NATO stands in solidarity with our valued ally, (it) is monitoring the situation and we will remain in contact as the facts are established," Stoltenberg said.

The Polish foreign ministry also summoned Moscow's charge d'affaires in Poland on Friday evening, and demanded that he "explain the incident of the violation of Polish airspace", according to a statement.

In November 2022, a Ukrainian air defence missile fell in the Polish village of Przewodow near the border, killing two civilians.

The explosion occurred at a grain storage site near a school about six kilometers (four miles) from the border during another intensive Russian bombardment of Ukraine.

There was initial doubt about whether the missile was Russian, raising concern that NATO could become directly involved in the war as member state Poland is covered by the alliance's collective defense agreement.