The northern Japanese city of Sapporo was shaken by an explosion that demolished a building housing a restaurant, damaged others and left 42 people wounded on Sunday night.

Photos and film posted on social media of the incident, and reproduced on TV news, showed rubble-strewn streets and flames illuminating the night sky. According to broadcaster NHK, it took firefighters several hours to extinguish the blaze that broke out after the explosion.

The two-story wooden building that housed the restaurant was virtually destroyed in the blast, which happened at about 8:30 pm. Neighboring structures that housed a real estate agency and a clinic were seriously damaged, a Sapporo fire department official told AFP.

Media reports said the incident may have involved gas tanks, but Sapporo police and fire officials investigating the blast said it was too early to pinpoint the cause, according to Reuters.

Sunday’s incident was not Sapporo’s first this year. In February, 11 people were killed in a fire at a social shelter, and the explosion is just the latest in a series of disasters that have left Japan reeling this year.

On December 12, the Japanese public, in a nationwide vote, chose the Chinese character for “disaster” as the symbol for 2018 – some 20,858 people out of 193,214 who voted chose the character. Throughout the year, Japan has been battered by a series of deadly heat waves, floods, earthquakes, landslides and storms that have killed hundreds, disrupted supply chains and even undercut GDP growth.