A suicide bombing early Tuesday at a mosque in northeastern Nigeria killed at least 50 people.
The attack, which President Muhammadu Buhari condemned as "cruel and dastardly," happened as people arrived for morning prayers at the mosque in the town of Mubi, located in Adamawa state.
In a statement, the president's office said the government would do "everything required to secure the state from the deadly menace of Boko Haram," the Islamist militant group suspected of being behind the attack.
There was no immediate claim of responsibility, but the bombing resembled numerous prior suicide attacks carried out by Boko Haram.
The militant group has killed more than 20,000 people during its eight-year insurgency against the government in a bid to create a strict Islamic state in the majority Muslim north.
The government has repeatedly assured Nigerians the insurgency is drawing to a close, only to see new attacks.