Thirty-four people died at the scene, Afinta said, and the rest died at hospitals.
“Mass commotion” followed the match, and the number of those killed was still being determined, the soccer league, Liga 1, said in a statement.
The stampede occurred after the home team, Arema FC, lost to Persebaya, at which point dozens of fans stormed the field, according to local media reports.
Videos showed fans scattered across the field as loud bangs and clouds of smoke erupted in the arena. Uniformed officers carrying riot shields were seen chasing down fans on the field and beating them with batons.
Matches were suspended for a week, the league said. “Hopefully this will be a valuable lesson for all of us,” said the head of the league, Akhmad Hadian Lukita.
Llewellyn reported from Medan, Indonesia.