Tokyo, Dec 17 (IANS): At least 42 people were injured in an explosion near a pub in Japan's Sapporo city, police said.

The blast occurred at around 8.30 p.m. on Sunday in the city's Toyohira Ward, causing a fire which was only extinguished hours later at 2.10 a.m., reports The Japan Times.

According to the police, the suspected gas explosion caused wooden buildings housing the Japanese-style pub, a real estate agency and a clinic to collapse

Among the injured, a male employee of the real estate agency was said to in critical condition.

The police suspect the explosion had occurred either at the pub or the real estate office.

Windows of houses and restaurants near the site, which is located close to a subway station, were shattered. Many people who felt the blast said they thought it was an earthquake.

A gas safety centre official who visited the blast site said five tanks of propane gas weighing 50 kg each were installed outside of the pub, while two 20 kg tanks were located outside the real estate office.

Gas pipes in the buildings were confirmed to be damaged after the explosion.

Sapporo, with almost 2 million people, is on Japan's large northern island of Hokkaido.