MOSCOW, April 28 (Xinhua) -- Seven people were killed in a fire at a private construction site in northern Moscow, Mayor Sergei Sobyanin said Tuesday.

The blaze broke out at a site in the Aeroport district, where emergency services and medical teams are operating at the scene, Sobyanin said on Telegram.

TASS news agency, citing emergency services, reported earlier that 13 other people were injured in the blaze, which spread across about 1,400 square meters and was later extinguished.

Investigators have opened a criminal case over suspected violations of safety regulations, according to the report.