SAN FRANCISCO >> San Francisco police and prosecutors are warning the city’s Chinese community to be aware of scam artists who have made off with almost $2 million this year by playing on the superstitions of older, Cantonese-speaking women.

The most recent cases happened over the Labor Day weekend, when two women in their 60s were told they and their cash and jewelry needed to be purified because they had stepped in blood and were being overtaken by evil spirits, Police Capt. Garret Tom said.

The victims — one of whom was approached in Chinatown on Sunday, the other waylaid in the South of Market neighborhood on Monday — turned over their valuables for a blessing. But the thieves, also women, made off with them by distracting their targets, according to a surveillance tape the police department released.

“They’re very comfortable with what they do because they’re very good with what they do,” said Lt. Arthur Stellini of the San Francisco Police Department’s special victims unit. “They train at this, they practice at this. They hone their skills just like anybody else.”

The bag of loot taken from one of the unsuspecting prey was worth $35,000. As of Wednesday, no arrests had been made.

In May, prosecutors announced the arrests of three women they say stole more than $100,000 worth of cash and jewelry from elderly women they approached on the streets with a similar scam.

Huifei Lin, 42, Caiqiong Chen, 43,  Lirong Lin, 57, were arrested as they tried to board an airplane to Hong Kong and are facing multiple counts, including grand theft and extortion.

Police Chief Greg Suhr said unsuspecting Chinese women in other major cities, including Boston, New York, Las Vegas and Seattle, have been swindled in the same way.

“Apparently, this is something that is effective,” he said.

District Attorney George Gascon said he planned to convene community meetings to warn San Francisco residents about the con.