The first bombing, which killed 17, ripped through a station on the outskirts of Potiskum, in northeast Yobe state, which has been targeted repeatedly by Boko Haram Islamists.
Roughly four hours later, two men blew themselves up after getting off a bus at a busy terminus in Kano, the north's largest city and another frequent Boko Haram target. Ten people were killed.
Despite the attacks, President Goodluck Jonathan said late Tuesday that the military had the insurgents on the back foot.
The Nigerian militant group, blamed for more than 13,000 deaths since 2009, has in recent weeks expanded its uprising into neighbouring countries, raising fears of a regional crisis.
In neighbouring Niger on Tuesday, a mine planted by the insurgents killed two soldiers and injured four others in the Diffa region bordering Yobe, a security source said.