A leak of household gas is reportedly the cause behind the explosion   / Photo from UNIAN

Kyiv Mayor Vitaliy Klitschko said the body had been found on the fourth floor, the press service of Kyiv City State Administration reported.

"An operation is under way to retrieve the body of a man killed in the explosion of the building in Pozniaky," he said. "Another resident of the same building is still missing."

Read alsoUp to three people could be left trapped under wreckage after Kyiv house gas blast (Photo, video)

As UNIAN reported, several apartments in a nine-storied apartment block at 1/5 Solomii Krushelnytskoi Street in Kyiv's Darnytsky district were damaged by an explosion at about 10:00 a.m. on Sunday, June 21. The explosion destroyed interfloor structures between the fourth and eighth floors.

A leak of household gas is reportedly the cause behind the incident.

More than 100 people lived in the destroyed part of the building, they were evacuated.

The incident is being investigated under Part 2 of Article 270 (violation of fire safety requirements established by law) of the Criminal Code of Ukraine.

Police conducted searches at the gas distribution company and all utilities firms that service the apartment block.

As of Monday morning, the casualties included three dead people, five were injured, and another three were rescued.