ABUJA, Nigeria  — At least 82 people were killed Wednesday by two bombings in the northern city of Kaduna, according to State Police Commissioner Umar Usman Shehu.

Opposition leader and former military ruler Muhammadu Buhari appeared to be the target of the second blast in a Kaduna marketplace but he was unharmed, according to a statement from Buhari.

The first blast appeared to target Sheik Dahiru Bauchi, who gave an annual Ramadan speech to thousands of faithful in an outdoor service. Bauchi is known for preaching against the violent extremism of Nigeria's Islamic terrorists, Boko Haram.

"They were waiting for him," said the police commissioner of the boy who threw a bomb at the sheik. "It's when he was passing the boy headed to him."

The sheik survived the blast but the boy was killed, said the police commissioner, who added that no arrests were made immediately.

The second blast, about two and a half hours after the first, appeared to be aimed at Buhari, and left bodies and body parts scattered, said witnesses. More than 50 vehicles were destroyed, the witnesses said.

A 24-hour curfew was declared by Kaduna state governor Mukhtar Ramalan Yero immediately after Wednesday's bombings, leaving many people stranded at their jobs, unable to go home for the night.

The governor did not directly blame Boko Haram but called the attackers a "common enemy" who are not true Muslims.

"Enemies of peace have visited us with their ungodly venom of wanton destruction of human lives," said Yero in a statement. "This blast, coming in the holy month of Ramadan is a clear indication that those behind the act have no iota of fear of God."

Boko Haram has killed thousands of people in five years of insurgency in Nigeria, including several prominent sheiks and politicians.

Kaduna is outside the region of Nigeria that is under emergency rule but it has been frequently targeted for violence by Boko Haram militants. In recent months, the Boko Haram insurgency has intensified, with near-daily attacks in the north, three bombings in the capital, Abuja, and more than 200 schoolgirls kidnapped and held captive now for 100 days.