Nigerian officials and clerics gathered for peace prayers in Kano Monday after a wave of attacks claimed by Islamists left more than 160 dead and raised fresh fears of civil unrest.
Nigerian President Goodluck Jonathan, facing his worst crisis since winning April polls amid a surge in attacks by Islamist sect Boko Haram and mounting social discontent, toured Kano on Sunday and vowed to beef up security.
Several bombs were set off and gun battles raged in coordinated attacks that were launched after Friday prayers in Nigeria's second largest city and lasted several hours.
Jonathan, after visiting the city on Sunday, said that some suspects had been arrested and that his government would track down the onslaught's masterminds.
"We will strengthen the security in Kano and other parts of the country," he said.
As the ancient holy Muslim city of about 4.5 million people still reeled from one of Boko Haram's bloodiest attacks, some 200 Muslim clerics and political leaders gathered at a mosque in the palace of the city's emir for special peace prayers.
"I will pray to God that we should never re-live the catastrophe that resulted in the deaths and maiming in our city," Kano State governor Rabiu Musa Kwankwaso said.
The emir Ado Bayero told the clerics: "I enjoin you to continue praying for peace and stability in our city. I call upon you to use any religious fora to pray for peace in our land."
"Without peace life would not be worth living and religion itself can't be practised."
A purported spokesman for Boko Haram claimed responsibility for the attacks, saying it was in response to a refusal by the authorities to release its members from custody.
Some people being detained at a police station in the city were thought to have been freed during the Friday attacks which targetted mainly police establishments and immigration offices.
Boko Haram is believed to have a number of factions with differing aims, including some with political links and a hardcore Islamist cell.
Jonathan who visited the emir and inspected bombed sites on Sunday vowed the Boko Haram backers would be tracked down and made to face the law.
"Those who are encouraging them, those who are sponsoring them, shall be brought to book," he vowed.
Jonathan is battling the worst crisis of his nine-month tenure as the violence has raised fears of an all-out civil war in Africa's most populous nation and top oil producer.
He has said some of the Boko Haram members have infiltrated government -- from the security agencies to the legislature and the executive arm of government.
Jonathan imposed emergency rule in parts of Nigeria's north on December 31 after a wave of violence blamed on Boko Haram, including attacks on churches on Christmas Day.
But Kano, which had escaped the worst of the violence in recent months, was not included in the areas covered.
Relief workers said the overall death toll fom Friday's attack was at least 166, but the authorities are only saying the number of dead would be over 100.
A doctor at a major hospital said the toll could soar to 250.
Nigeria's supreme Muslim leader, the Sultan of Sokoto Sa'ad Abubakar, condemned the Friday attacks.
In a statement, Abubakar said the Kano "incident is perhaps the worst in terms of the loss of lives and property."
"It is evidently clear that Nigeria is passing through a trying moment of general insecurity of overwhelming magnitude," said the Sultan.
Friday's strikes would be among the group's most brazen and well-coordinated assaults by Boko Haram.
Most of the recent major attacks have occurred in the northeast of the country, with many taking place despite the state of emergency.
The group claimed responsibility for the Christmas Day bombing of worshippers outside a Catholic church near the capital Abuja, which killed at least 44 people.
It also claimed the August suicide bombing of UN headquarters in Abuja that killed 25 people.
Attacks specifically targeting Christians have given rise to fears of a wider religious conflict in the country, which is roughly divided between a mainly Muslim north and predominantly Christian south.
But attacks blamed on Boko Haram have included a wide range of targets, including Muslims.