Associated Press/David Goldman
Ernesto Vergne prays at a cross honoring his friend Xavier Emmanuel Serrano Rosado and the other victims at a memorial to those killed in the Pulse nightclub mass shooting a few blocks from the club early Friday, June 17, 2016, in Orlando, Fla.
Omar Mateen was interred at the Muslim Cemetery of South Florida outside of Miami, several news outlets including the Orlando Sentinel reported.
Mateen was fatally shot by police during the massacre at Pulse nightclub that killed 49 people earlier this month.
The grave is unmarked, and media outlets only learned of the burial by checking death records.
One man said he's considering having his wife exhumed and moved to another cemetery.
"I don't see her resting in peace among people like that," Andrea Wade, whose wife is buried 30 yards from Mateen, told NBC News.
Others objected to Mateen's burial on religious grounds.
"He's claiming he's a Muslim," Sultan Mamun, whose father is buried at the cemetery, said. "But we don't believe he is a Muslim because our religion doesn't permit killing."
Mohammad Dandia, who works at the cemetery, called Mateen's actions "horrendous," but wouldn't judge whether the decision to bury him there was right or wrong.
"He has to be buried somewhere, right?" he said, according to South Florida's WPLG.