San Francisco police arrested a person for allegedly throwing a Molotov cocktail at OpenAI CEO Sam Altman’s home and for making threats outside the artificial intelligence startup’s headquarters, the company said on Friday.

In a post on X, the San Francisco Police Department said an unknown male threw an incendiary device at a North Beach residence at 4:12am and then escaped on foot. The 20-year-old suspect was detained about an hour later after police received a call about a man threatening to burn down another building.

Police did not immediately comment on the suspect’s potential motive.

Read: OpenAI calls for sweeping economic reforms amid rapid growth of artificial intelligence

“Thankfully, no one was hurt. We deeply appreciate how quickly SFPD responded and the support from the city in helping keep our employees safe,” an OpenAI spokesperson said. The company is assisting law enforcement agencies with their investigation, the spokesperson added.

The incident came as OpenAI faces intense pressure. The company recently faced backlash ​over its move to strike a deal with ​the US ⁠government to let it use its technology in classified military operations, after rival Anthropic and Washington got into a dispute.

A recent NBC News poll found that AI is less popular than US Immigration and Customs Enforcement (ICE).

Read More: Anthropic sues to block Pentagon blacklisting over AI use restrictions

Altman addressed the incident in a blog post published on Friday afternoon. “A lot of the criticism of our industry comes from sincere concern about the incredibly high stakes of this technology,” he wrote. “While we have that debate, we should de-escalate the rhetoric and tactics and try to have fewer explosions in fewer homes, figuratively and literally,” he later added.

San Francisco police said officers investigating the fire at Altman’s house found signs that the 20-year-old was involved.