Suicide bombers suspected to be Boko Haram extremists killed over 30 people in twin blasts in Nigeria since late Monday, turning the heat on new President Muhammadu Buhari.
The attackers detonated a device at a local government building on the outskirts of the city of Zaria, killing 25 people and wounding 32 others on Tuesday, said Nasir el-Rufai, governor of Kaduna state.
Around the same time, another suicide bomber killed herself and four others at a military checkpoint in Borno state.
"A young lady wearing a veil with explosive devices strapped at her body detonated an IED at a checkpoint ... before she was checked," a military spokesperson said.
A teenager female bomber was killed on Monday as the bomb planned for a mosque in Kano went off before time.
These attacks follow suicide bombings on Sunday in Jos that killed about 40 people, and an earlier string of attacks and raids that left 200 or more dead.
"We call on our citizens to be vigilant and avoid crowded places like markets, mosques, churches and motor parks in the next few weeks," El-Rufai said on his Facebook page.
The recent attacks are a blow for the Buhari administration, which came to power in a campaign that promised to crush the six-year Islamist insurgency in the north.
Boko Haram plans to carve out its own Islamic state in Nigeria. Nigeria and its neighbours Cameroon, Niger and Chad have formed a regional military coalition to tackle the jihadists.
The militants are clinging to a last stronghold in the Sambisa forest reserve while many have dispersed throughout the country, reports Reuters.
Tuesday also saw Boko Haram fighters cross over into Cameroon where they clashed with security forces, leaving three of the militants dead.
At least 1.4 million people have been forced to flee their homes as of June, according to data from the International Organization for Migration.