Darien police are warning residents about a sexually explicit letter that has been sent to several local women.

According to Darien detectives, the identical letters were delivered Monday to at least 10 women in white envelopes bearing either a Westchester County or a New York City postmark.

Police say in the letter, the sender uses graphic language to request a sexual encounter. Darien authorities say it doesn't appear any particular woman has been targeted, although specific names and addresses were used.

Sgt. Jeremiah Marron, of the Darien Police Department, says the postal authority is collaborating with police to determine where the letters came from.