Two explosions killed at least 73 people in Beirut, the capital of Lebanon, on Tuesday, AFP reported. As many as 3,700 people were injured in the explosions, which destroyed Beirut’s port, according to the Health Ministry.

Interior Minister Mohammed Fahmi said it was likely that ammonium nitrate being stored in a warehouse at the port caused the first blast. The second one set an orange fireball into the sky, devastating the harbour and shattering windows several kilometres away. Buildings 10 km away from the site of the blast were damaged.

United States President Donald Trump said his military generals told him they “seem to feel” that the massive explosion was in fact a bomb attack, AP reported. “I met with some of our great generals and they just seem to feel that it was [an attack],” Trump told reporters at the White House. “This was not a – some kind of a manufacturing explosion type of a event...they seem to think it was a attack. It was a bomb of some kind, yes.”

Lebanese Prime Minister Hassan Diab said 2,750 tonnes of ammonium nitrate were stored in the Beirut port warehouse, AFP reported. “It is unacceptable that a shipment of 2,750 tonnes of ammonium nitrate has been present for six years in a warehouse, without taking preventive measures,” he said at an urgently convened defence council meeting, according to a spokesperson. “It is unacceptable and we cannot remain silent on this matter.” Diab announced a day of national mourning on Wednesday.

The blast came a day ahead of a court verdict in the trial connected with the killing of former Prime Minister Rafik Hariri. A tribunal of the United Nations is expected to give its verdict in the case of Hariri’s death in 2005, which involves four suspects.