(CNN)Six people were killed after a car crashed into a crowd of people who had gathered to attend a local carnival on Sunday morning in Strépy-Bracquegnies, near La Louvière, Belgium.
Abnother 10 people were sent to nearby hospitals with life-threatening injuries and 27 were "slightly injured," Deputy Crown Prosecutor Damien Verheyen said.
As a group of carnival-goers were marching towards the town center, "a car came from the back at high speed and crashed into group, pulverized a large number of people, continuing its way before stopping a little further down," La Louvière mayor Jacques Gobert told reporters.
The two men who were in the car, both from La Louvière and born in 1988 and 1990, were arrested, Verheyen said. He added that a "reconstruction of the facts" will be held in order to establish the exact route of the vehicle and any potential motive.
The incident happened at 5 a.m. local time. Strépy-Bracquegnies is located 30 miles (50km) south of Brussels.
There was no evidence that a chase with police led to the incident, officers said, contrary to earlier reports. They also said as yet "no elements" showed that the incident "could be considered as a terrorist attack."
Authorities said five emergency vehicles and 16 ambulances were sent to the scene to transport the victims to various hospitals in the region -- 70 non-injured people were evacuated from the scene.
Belgium's King Philippe and Prime Minister Alexander De Croo were expected to visit the scene on Sunday at 4 p.m. local time.
De Croo wrote on Twitter that "his thoughts were with victims and their relatives."
"Horrible news from Strépy-Bracquegnies. A community gathering to celebrate has been hit in the heart," he wrote.
Interior Minister Annelies Verlinden also tweeted her condolences "to the families and friends to those who died and were injured" in the incident.
"What was supposed to be a friendly party turned into a tragedy. We are following the situation closely," she wrote in a tweet.