Belgium police and helicopters are surrounding the area. (Reuters/RTL/Sky)

Brussels (People's Daily) - Belgium police Thursday sealed off part of a Brussels suburb, where the mayor said a suspected gunman could be at large.

Images from the scene showed heavily armed police hiding behind buildings and scouting the rooftop of a building in the Forest district of the Belgian capital. A police helicopter could be heard overhead. The police response began at around lunchtime.

A Belgian police officer prepares his gun while taking a position on a roof. (Reuters)

Forest Mayor Marc-Jean Ghyssels told local broadcaster RTL that police "suspect the presence of an armed man, or several men."

"There is nothing to indicate it has anything to do with terrorism,” Ghyssels said.

A spokeswoman for Belgian police said that "special units of the federal police" had been deployed after a man reported that someone had been murdered on Thursday morning. “They are searching the buildings but we can say there has not been any terrorist attack.”

Photo via AP live streaming videos

Forest made international headlines in November 2015 after Salah Abdeslam, a suspect in the deadly Paris attacks, hid there and became involved in a gun battle with police.

Brussels has been on high alert since suicide bombers killed 32 people at the city airport and on the metro in March 2016.

Last month, Prime Minister Charles Michel announced that Belgium's terrorism threat level had been reduced from three to two, stating that there was "little likelihood" of an attack.