Updates with new casualty figures.
A military aircraft crashed Monday into a residential building in the southern port town of Yeysk in Russia's Krasnodar region, Interfax news agency reported, citing local officials.
Fourteen people were killed and 19 injured, according to regional emergencies officials cited Tuesday by RIA Novosti.
The crash was probably caused by "a technical malfunction," Russia's Investigative Committee, which probes serious crimes, said.
It said it had launched a criminal inquiry into possible violations of flight rules and had "seized fuel samples at the departure aerodrome" and "flight recorders at the site of the crash."
Footage posted on social media showed a multi-story apartment building engulfed in flames as additional explosions took place.
The Defense Ministry said that the pilots had both ejected safely, and one video circulating on social media what appeared to be pilot, lying on the ground near the burning building, alive but apparently injured.
Since the beginning of the Ukraine offensive, the airspace around the south of Russia has been closed.
AFP contributed reporting.