Updated at 10:45 a.m. ET on Oct. 13.

German officials say a Syrian man arrested on Monday for allegedly planning a bomb attack has killed himself.

Jaber al-Bakr was being held in a detention center in Leipzig, Germany, The Associated Press reports. On Thursday, the wire service reported that the head of the center, Rolf Jacob, told reporters "that a trainee guard checked on the prisoner at 7:30 p.m. Wednesday, and that when he returned for another check at 7:45 p.m. he found al-Bakr hanging lifeless."

News reports citing Germany's Spiegel Online had previously said al-Bakr had been under constant surveillance because he was deemed at risk for suicide, but Jacob said Thursday that authorities who assessed al-Bakr did not consider him at acute risk for suicide, according to Deusche Welle.

German justice ministry spokesman Joerg Herold told the AP that al-Bakr killed himself sometime in the evening on Wednesday, and that the incident was being investigated.

Authorities earlier said he was likely linked to ISIS.

NPR's Soraya Sarhaddi Nelson reports al-Bakr was arrested after a nationwide manhunt over the weekend, which started Saturday when German intelligence agents tipped off police. The police raided an apartment in Chemnitz, Germany, where Soraya reports they found "fuses and three pounds of explosives, including what authorities think is TATP."

TATP is a volatile chemical used in the bomb attacks earlier this year in Brussels and Paris.

During the Saturday raid, Soraya reports the police saw al-Bakr fleeing. They fired a warning shot but did not chase him.

He was caught on Monday, after he asked fellow Syrian refugees for help. They recognized him from wanted posters, held him at an apartment in Leipzig and delivered him to the police tied up, Soraya reports.

As the Two Way reported on Monday:

"In addition to gathering explosive materials, al-Bakr had searched for instructions on how to make 'equipment for jihad,' the AP reports, but investigators say there's no evidence he had selected a target to attack."

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