A suitcase bomb packed with nails and gas bottles could have caused heavy casualties, Belgium’s prime minister said on Wednesday, a day after a soldier shot dead a Moroccan national attempting an attack on Brussels’ Central Station.

“We have avoided an attack that could have been a great deal worse,” Charles Michel told reporters on Wednesday following Tuesday evening’s incident, in which no one else was hurt. No further threat was imminent and the alert level was unchanged.

A security source named the dead man, identified officially only by the initials O.Z., as Oussama Zariouh. A counter-terrorism prosecutor said he was a 36-year-old Moroccan citizen who lived in the Brussels borough of Molenbeek and had not been suspected of militant links. He set off his bomb on a crowded station concourse below ground at 8:44 p.m. (2.44 p.m. ET).

Walking up to some passengers, “he grabbed his suitcase, while shouting and causing a partial explosion. Fortunately, nobody was hurt,” prosecutor Eric Van Der Sypt said.