Moscow, Nov 18 (IANS) 

All 50 people on board a Boeing 737 plane were killed when it crashed in a Russian city while landing Sunday, Russian authorities confirmed. There were no survivors.

The accident occurred in in Russia's Kazan city, capital of Tatarstan republic, when the plane, belonging to Tatarstan Airlines, crashed about 7.20 p.m. Sunday. 

According to the Russian Emergency Situations Ministry, the deceased comprised 44 passengers and six crew members, Xinhua reported. Earlier the toll was reported to be 52 comprising 46 passengers and six crew. 

Irek Minnikhanov, son of Tatarstan's President Rustam Minnikhanov, and Alexander Antonov, the republic's security service chief, were among the killed, said Tatarstan Republic's deputy prime minister Yury Kamaltynov.

The National aviation watchdog Rosaviatsia said the plane was about to fly a second circle before landing.

The cause of the crash was yet to be determined as the black boxes had not been found.

Russian President Vladimir Putin expressed condolences to the families of the killed, said Kremlin spokesman Dmitry Peskov, adding that the president also instructed for setting up an investigation commission for the air crash.

Russian Investigative Committee, the country's criminal investigative body, said it would send experts to the site of the air crash, and the committee head Alexander Bastrykin would fly to Kazan Monday. 

Tatarstan authorities declared Monday as the day of mourning for the air crash victims.