Fifty people have been killed after a passenger jet crashed in the Russian city of Kazan, the worst such tragedy in the country in more than two years.

The Boeing 737-500 from Moscow exploded after a failed attempt to land at the Kazan international airport,

according to the Ministry of Emergency Situations in the Republic of Tartarstan.

Officials said that the plane had attempted to land several times prior to the crash.

The Tatarstan Emergency Situations Ministry said 44 passengers and 6 crew members were confirmed dead, but told Interfax News Service that as many as 52 could have been killed in the explosion.

The crash was reported at 7:20 p.m. (10:20 a.m. EST), according to Interfax.

The flight was operated by the regional Tatarstan airline, a ministry spokeswoman told Reuters.

Sunday’s crash was the deadliest in Russia since an incident in September 2011 when 44 people were killed when a Yak-42 plane crashed near the town of Yaroslavl, wiping out almost all of the Yaroslavl Lokomotiv ice-hockey team.