U.S. missionary Phyllis Sortor was kidnapped by several people in the central Nigerian state of Kogi on Monday, according to her church.

"Rev. Phyllis Sortor, our missionary in Nigeria, was abducted from the Hope Academy compound in Emiworo, Kogi State, Nigeria," Bishop David Kendall said in a statement posted on the website of the Free Methodist Church. "The U.S. Embassy has been notified, and the State Department and the FBI are working with local authorities to find and rescue her."

An American woman was abducted and a search and rescue operation is underway, Emmanuel Ojukwu, a national police spokesman, said by phone earlier from the capital, Abuja. He declined to give further details.

Kidnappings for ransom are frequently carried out by criminal gangs in Nigeria. In the north, the Islamist militant group Boko Haram has increasingly used abductions in its campaign to impose Islamic law on Africa's largest oil producer. In April, the group seized more than 200 girls from a school in northeast town of Chibok, provoking an international outcry.

"We are aware of media reports that a U.S. citizen was reported missing in Nigeria," the U.S. State Department said in an emailed statement on Tuesday. "In cases where U.S. citizens are confirmed missing, the U.S. embassy works closely with those involved, supporting local authorities in their search efforts, and providing all appropriate consular assistance."