The United States has made official what Nigeria’s churches have long asserted: Boko Haram is a terrorist organisation.

The state department announced on Thursday it has designated Boko Haram a “foreign terrorist organisation”, and as “specially designated global terrorists”. The Islamist insurgent group “is responsible for thousands of deaths in northeast and central Nigeria over the last several years including targeted killings of civilians”, according to a state department release. In its announcement, the state department did not mention Boko Haram’s numerous and deadly attacks on Christians, but a U.S. senior administration official told journalists on background that Boko Haram is “responsible for thousands of deaths since its conception in 2009, including large-scale attacks against Muslim and Christian religious communities, and women and children.”

At the same time, the state department also imposed the same designations on Ansaru, a Boko Haram splinter group. The designations authorise the U.S. Treasury Department to seize the groups’ assets, and make it illegal for any American to provide assistance to them.