There was no claim of responsibility by an armed Palestinian group, but a man calling himself Hadi Saud contacted The Associated Press in Nablus and said he was the kidnapper.
He demanded a job in the Palestinian security forces and medication for a shooting injury sustained last year, in exchange for releasing the hostages. He provided no proof that he is holding the women.
The security officials said the three women were last seen taking pictures on the outskirts of the Balata refugee camp near Nablus. The officials did not release the names of the three.
Micaela Schweitzer-Bluhm, a spokeswoman for the U.S. Consulate in Jerusalem, said U.S. officials were informed of the kidnappings. "We take them extremely seriously," Schweitzer-Bluhm said.
She said American officials were in touch with Palestinian security. She had no details on the identities of the women or what they were doing in the West Bank.
In the past, scores of foreigners were kidnapped by various Palestinian militant groups, but usually released unharmed after a few hours.