Jakarta. A man who fired an airsoft gun at the Indonesian Ulema Council (MUI) building in Jakarta on Tuesday and died after a physical altercation with a security guard had mental problems, police said.

The gunman was identified as Mustopa, 60, whose cause of death remained unknown pending the autopsy. 

Authorities dismissed a link of his action to terrorism after it was learned that he was an ordinary farmer from Pesawaran Regency in the province of Lampung with a history of a serious mental illness.

Mustopa was once sentenced to five months in prison for vandalizing the office of the Lampung Legislative Council, Pesawaran District Police Chief Adjunct Chief Comr. Pratomo Widodo told reporters.

Family members suspected that Mustopa had had mental issues since 2016 when he began to proclaim himself as a prophet’s messenger.

"But despite his mental condition, he had never been admitted to the hospital," Pratomo said.

He departed for Jakarta a day before he came to the MUI building.

His younger brother who introduced himself as Ichwan said Mustopa was once restrained in stocks when he lived in his wife’s hometown because neighbors considered him a risk to their safety. 

After he was said to have recovered, Mustopa returned to his daily activities as a cocoa grower in Pesawaran without showing any strange behavior, the brother said.

"There was no sign of any radical behavior. I was shocked upon hearing the news like this," Ichwan said.

Mustopa arrived at the building on Tuesday morning and demanded to meet MUI Chairman Miftachul Akhyar in person.

According to witnesses’ accounts, receptionists and security guards rejected his request because he couldn’t explain his intention and he responded by firing the gun that smashed the glass door and injured two people.

He was still alive when a security guard grappled with him and took the gun, but he was pronounced dead at a nearby medical facility.

Warning: The following video contains scenes that some may find disturbing.