ABUJA, June 13 -- President Bola Tinubu has ordered Nigeria's bandits, kidnappers and the financiers behind them to surrender or face the full force of the state, using a Democracy Day address to project resolve over a security crisis that, by his own account, has begun to ease even as mass abductions push into new parts of the country.

To bandits, kidnappers, and sponsors of terror, surrender or face the full force of the Nigerian State, Tinubu said in the June 12 speech marking the anniversary of the country's return to democratic rule. These windows of surrender will not remain open forever. No mercy will be shown to those who trade in the blood of Nigerians.

The president backed the warning with numbers. His government, he said, had...