Police shot one man as they arrested seven - including one identified as the second suspect in the bombing of a metro station - Belgian media reported, in several Brussels neighbourhoods in raids following the multiple terror attacks that killed 31 people earlier this week.
The operations began on Thursday night and continued yesterday as France thwarted a deadly terrorist plot "at an advanced stage" with the arrest of a man in the suburb of Argenteuil near Paris.
Germany also detained two suspects, bringing the total nabbed to 10 since European nations stepped up efforts to prevent further attacks in the wake of the Brussels bombings.
In the neighbourhood of Schaerbeek, not far from the Belgian capital, explosions and gunfire were heard yesterday afternoon after police cordoned off the area while searching a house.
At press time, there were unconfirmed reports that police had shot a man in the right leg. Belgian public broadcaster RTBF quoted local mayor Bernard Clerfayt as saying that the person was linked to the bomb attacks in Brussels and the foiled plot this week near Paris.
Heavily armed policemen and military personnel with trucks cordoned off an area around a major intersection and three blasts were heard. Mr Clerfayt said those were controlled explosions.
Broadcaster RTL reported that the police used a bomb-disposal robots in the raid.
The TV station also quoted a witness as saying police approached a person at a bus stop and asked the person to remove a jacket.
"No doubt to check if the person had an explosives belt strapped on," the witness told RTL.
The witness said it was not clear if the person had been wounded, but the person was lying on the ground and talking to the police, Reuters reported.
RTBF cited unidentified sources as saying the person arrested had not responded to police orders and had been found to be in possession of a suitcase containing explosive substances.
Police operations on Thursday and yesterday have focused on Schaerbeek, where Tuesday's suicide bombers Ibrahim and Khalid el-Bakraoui had hidden in a flat in which 15kg of explosives, detonators and a suitcase filled with nails and screws were later found.
One of the seven people arrested overnight was nabbed in Schaerbeek, while three were taken from a car in front of the federal prosecution building for "stupidly hanging around" there, Reuters reported a source close to the investigation as saying, noting that investigators were still trying to establish if the trio were reconnoitring an attack on the area.
Belgian daily De Standaard said another man taken in was a suspect seen on closed-circuit television cameras talking to Khalid, who blew himself up inside Maelbeek metro station near the European Union headquarters.
"We have strong indications that this is the suspect who was hunted for the last couple of days," the Reuters source said. "The identification is still ongoing."
Another suspect, caught on surveillance cameras at Brussels Airport, is believed to still be at large.
A new name that emerged as a suspect in the bombings was that of Naim al-Hamed, a 28-year-old Syrian. Belgian media, citing police, have described him as "armed and very dangerous". He is believed to have been involved in the November Paris attacks as well.
Yesterday, United States top diplomat John Kerry arrived in Brussels in a show of support for Belgium, a day after Europe's interior ministers met in the city to discuss stronger anti-terror cooperation.
Standing next to Belgian Prime Minister Charles Michel, Mr Kerry said: "We will not be intimidated. We will not be deterred."