KIEV, September 26. /TASS/. Authorities in Ukraine’s Kharkov region declared Saturday a national day of mourning for those who were killed in the An-26 plane’s crash, the local administration said.

"On the day of mourning across the entire region’s territory Ukraine’s national flag at all buildings of state power, enterprises, agencies and organizations will be flown at half-mast and a mourning ribbon will be placed on it," the governor said in his decree published on the administration’s website.

All entertainment and sports events should be canceled according to recommendations.

An An-26 military transport plane crashed in the Chuguyev district of northeastern Ukraine’s Kharkov region during a landing approach. A total of 27 people were onboard the plane. Apart from the crew, the plane had cadets of the Ivan Kozhedub National Air Force University on board, and was performing a training flight. According to the latest data, 25 people were killed. Two cadets managed to jump out of the plane, but they sustained injuries to about 90% of body surface, Kharkov Region Governor Alexei Kucher said.

According to the governor, the tragedy was probably caused by a failure of the plane’s left engine. However, according to the official, "a failure of one engine is not critical for an experienced pilot." Another version of the disaster was voiced by Ukraine’s former chief military prosecutor Anatoly Matios, who said the disaster was caused by the crew’s error during landing. He attributed the information to his own sources in the Defense Ministry of Ukraine.

The plane was manufactured in 1977 and in late July the Air Force’s command signed a contract with the Antonov plant to extend the service life of nine warplanes, including the crashed An-26, the Strana newspaper reported.

Ukrainian President Vladimir Zelensky announced that he would come to Kharkov on Saturday and demanded that a thorough investigation into the tragedy be carried out.