Japan: blast in building in Tokyo; at least 4 injured, say reports

An explosion occurred inside a building in Japan's capital city Tokyo on July 3.

The blast occurred at around 3:15 pm in Tokyo's commercial district of Shimbashi.

Visuals circulating on social media showed smoke, shattered windows, and debris on the street.

At least 4 persons were injured, as per media outlet NHK. The cause of the blast was not immediately clear.