One person died and four sustained minor injuries after an explosion rocked a residential building Sunday morning in Xi'an, capital of northwest China's Shaanxi province, local authorities said.

The accident happened at around 5:10 a.m. Sunday in an apartment on the 13th floor of a 24-story building in the Chunxiaoxinyuan residential area.

Witnesses said a man fell to his death from the building during the explosion, and several neighboring apartments on the same floor were also severely damaged.

The building has been evacuated, and the four people who were injured are being treated in hospital.

A preliminary investigation shows that the accident was triggered by improper use of natural gas, police said.

A comprehensive safety check on the building's facilities is being carried out.