An explosion at a sports centre in the Belgian town of Chimay has killed at least one person and wounded four others, two of them seriously, Belgium's Crisis Centre says.
"It is probably a gas explosion," an official at the agency told Reuters, adding that there was no indication of it being a militant attack.
"We are not 100 percent sure, but, most likely, we are dealing with a gas explosion due to a suicide. There are no other explanations," a crisis center spokesperson told RIA Novost.
Local media reported the blast occurred just after midnight at a sports centre known as "Le Chalon" in Chimay, close to the French border, when five people were still inside the building. Part of the building was destroyed.
Belgium and France, along with the rest of Europe, have been on high alert after Islamic State attacks in Paris and Brussels over the past year.
Brussels was hit by attacks at the airport and subway on March 22 that killed 32 people.
More to come.