BRUSSELS—A lone assailant wielding a knife injured three people in Brussels on Monday during a rush-hour rampage through a subway car before being detained by police in the station under the European Union’s headquarters, officials said.

The Brussels prosecutor’s spokesperson, Martin Francois, said one of the three injured people was taken to hospital and remained in a “life-threatening” condition. The two others were treated for lesser injuries.

Francois told the Associated Press that at first sight “there were no indications of terrorism.” He said the suspect was a 30-year-old male.

Social media posts showed police with their guns pointed at a man at the Schuman station, while others showed a man wrapped in warming foil being attended to by first aid officials outside it. The station is directly under the main office of the EU’s executive Commission.

The Brussels incident took on special significance after last week’s killing of a church official by a machete-wielding assailant in southern Spain.

In Germany two teenagers were stabbed to death and five other passengers injured on a train in northern Germany.

AP reporters on the scene in Brussels Monday said the area was quickly sealed off during the evening rush hour incident. Main broadcasters like RTL and VRT said panic briefly broke out in the subway station before order was restored.

By Raf Casert