Belgian police locked down several streets in Brussels amid reports of a gunman at large. However, police have now ruled out any instance of foul play and de-escalated their alert.

Specialist armed units could be seen surrounding the building near the Place Saint-Denis in the Forest district, in the south-west of Brussels on Thursday (22 February). Residents were told to stay in their homes, and a nearby primary school with 350 pupils were told to stay in their classrooms.

Helicopters were ordered to the scene and two apartments were searched, following witness reports that an armed man could be at large in the neighborhood.

It was unclear if the man was thought to be acting alone, or whether there were other armed men with him. Police were first called to the scene at around lunchtime.

However, the area was opened up to the public after about three hours and police spokeswoman Kathleen Calie confirmed the incident was not terror-related.

Earlier, broadcaster RTL quoted Forest mayor Marc-Jean Ghyssels as saying that police "suspect the presence of an armed man."

The incident began after a Polish man reported someone had been murdered there in the morning.

Other witnesses also said they saw an armed man in a nearby building, which triggered the call for armed police units. But following a search, officers found no body and no gunman.

Police spokeswoman Calie said:"It seems [the Polish man] may have expressed himself badly. We can rule out terrorism."

Belgium recently lowered its terror threat level after almost two years on high alert, after suicide bombers killed 32 people at the Zaventem Airport and at the Maalbeek metro in March 2016.

Salah Abdeslam, a suspect in the deadly Paris attacks in November 2015, hid in the Forest area of the capital, and was captured in a shootout with police in a nearby apartment in March 2016. He was eventually arrested, with his trial expected to begin in 2019.

Specialist armed units prepare to surrounded a building in the Belgian capital, where a gunman, or gunmen are holed up
Specialist armed units prepare to surrounded a building in the Belgian capital, where a gunman, or gunmen, are holed up Reuters