French anti-terrorism police, on alert since the attack on Charlie Hebdo magazine and a kosher market, made arrests in an alleged plot to attack a French church. Religion News Service photo by Maya Vidon

PARIS (Reuters) — French police were holding three people for questioning on suspicion they may be accomplices of an Algerian man suspected of planning to attack at least one French church, several French media said on Sunday.

The Paris prosecutor’s office declined to comment.

French magistrates have already placed the 24-year-old Algerian, who is suspected of murdering a woman and planning a gun attack on churchgoers in a Paris suburb, under formal investigation on Friday.

Le Figaro.fr, citing a source close to the matter, said the three men arrested over the weekend were questioned on Sunday by the anti-terrorism section of the Paris police. The DNA of two of them had been found in the Algerian suspect’s appartment.

The Paris chief prosecutor said earlier this week a search of the Algerian suspect’s phones and laptops showed he was in touch with another person, possibly in Syria, who had asked him to target a church. Authorities have said they believe one or more attacks were imminent.

France remains on high alert three months after Islamists killed 17 people in attacks on the satirical weekly Charlie Hebdo, which had mocked Islam and other religions, and on a Jewish food store. Authorities say five attacks have been foiled since then.

(Reporting by Dominique Vidalon, Sophie Louet; Editing by Larry King)