Moscow, Feb 3 (IANS): Temporary restrictions on the arrival and departure of aircraft have been imposed at the Russian airports of Astrakhan, Kazan, Ulyanovsk, Nizhnekamsk, and Saratov, authorities said on Monday.

The temporary measures introduced early Monday morning are "to ensure the safety of civil aircraft operations," Artem Korenyako, a representative of the Russian Federal Air Transport Agency, said in a Telegram post.

Korenyako emphasised that "aircraft crews, air traffic controllers, and airport services are taking all necessary measures to ensure flight safety, which remains the top priority."

The announcement follows heightened security concerns after reports of a drone attack in the Astrakhan region. Astrakhan governor Igor Babushkin said that Ukraine launched a drone attack overnight, attempting to attack facilities in the region.

"Electronic warfare and air defence systems operated as intended... There were no casualties," Babushkin said on his Telegram channel, Xinhua news agency reported.

Sergei Efremov, Vice Governor of Russia's Primorye Territory and former Commander of the Tiger volunteer unit, was killed while returning from a combat mission, Regional Governor Oleg Kozhemyako said Sunday.

"It is a day of great sorrow for us... He was an outstanding person with a kind heart, a strong-willed leader and an organiser," Kozhemyako said in a video message on his Telegram channel.

Efremov has led the Tiger volunteer unit since its establishment in 2022. In 2024, he was appointed Vice Governor of Primorye, overseeing the regional's domestic policy. He returned to the front lines following Ukraine's offensive in the Kursk region.

He is the highest-ranking Russian official to have been killed in the Russia-Ukraine conflict.

The death of a high-ranking official has caused a wide public outcry, and additional information from official sources is expected in the near future, Russian media reported on Monday.