Three people were killed and eight others were injured in a hospital fire in the central Russian city of Ryazan early on Wednesday, Tass news agency reported citing Russia's Emergencies Ministry.

The fire broke out at an intensive care unit of a hospital at around 3:36 a.m. local time and was fully put out within an hour. 

Victims are patients undergoing treatment from severe COVID-19 complications, the agency said.

Two of the deceased were found dead on site while the third person, a woman, passed away en route to the hospital. 

The cause of the fire is not immediately clear and an investigation has been launched.