PHILADELPHIA (CBS) — The Cambodian Association of Greater Philadelphia is speaking out against a threatening letter sent anonymously to its South Philadelphia office. Meanwhile, Philadelphia Police say they have identified a person of interest.

Police say a 79-year-old woman claims to be the author of the letter. Authorities will give an update on the investigation at 3 p.m. Friday. They also say many of the claims in the letter are untrue.

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“I’ve been with the association for nearly 12, 13 years now,” said CAGP Executive Director Sarun Chan. “We’ve never experienced a threat like this. It’s blatant ethnic intimidation.”

Chan declined to go into the specifics but said the writer targeted people of Cambodian descent who use nearby Mifflin Square Park.

“It involved killing and murdering community members, and we took the threat 100% seriously,” he said.

Philadelphia police say the author claimed to be a former military member, writing that fireworks set off by Cambodian residents in Mifflin Square Park are affecting their sleep.

The author wrote that if the fireworks did not stop, they would harm the residents using weapons they had available.

Through an investigation, police found the 79-year-old woman is not a former member of the military and doesn’t appear to have access to weapons.

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The letter was so unsettling that for the time being Mifflin Square Park is not being used by CAGP’s summer camp. Philadelphia has the fourth-largest Cambodian population in the country, many of whom live and worship in South Philly.

“All along here, are multiple Cambodian businesses, so we are a predominant force in this community,” Chan said.

The association immediately called police and put out its own letter informing the families they serve about the threatening nature of the letter. The incident has community members on heightened alert, but Chan said it’s also a call to action against Anti-Asian hate.

“We’re distraught. But we’re not going to be silenced,” he said. “We want to make sure that we address this head-on and that we still amplify our visibility and our voice.”

Friday at 3 p.m. at Mifflin Square Park, the Cambodian Association of Greater Philadelphia will hold a news conference alongside other community groups, leaders and city agencies to update the community on the response to this incident.

Police say they have forwarded their findings to the District Attorney’s Office for review and possible charges.

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CBS3’s Trang Do contributed to this report.