By Lanre Ola and Ibrahim Mshelizza
MAIDUGURI, Nigeria (Reuters) - At least 17 people were killed on Tuesday in a car bomb in Nigeria's northeastern city of Maiduguri, the epicenter of an Islamist revolt in Africa's largest oil producer, police and witnesses said.
No one claimed responsibility for the blast. But militant sect Boko Haram, which was founded in the city, has continued to attack schools and government and military targets in the face of army crackdown on its four-year-old revolt.
The bomb, planted in a three-wheel rickshaw taxi, exploded outside the state television offices at around 1.30 pm (1230 GMT), witnesses told Reuters.
"My men counted 17 dead as at 2:00 pm and they are still counting. I have instructed my men to go to the University of Maiduguri Teaching Hospital and the state specialist hospital to verify if there are others," said Borno Police Commissioner Lawan Tanko.
"I saw two boys on the ground and their bodies cut into pieces, two other cars immediately caught fire and I ran away because there was too much blood," city resident Aisha Hassan told Reuters.
Soldiers fired shots into the air to disperse crowds before cordoning off the roads around the bomb site, witnesses said.
Dozens of youths, some armed with machetes, protested on the street after the attack, accusing politicians of failing to curb violence in Maiduguri, they said.
President Goodluck Jonathan stepped up a military campaign against the group in May last year. But it has not stemmed the violence which killed thousands last year, security experts say.
The radical Islamist sect says it is fighting to create an Islamic state in a country of nearly 170 million split roughly equally between Christians and Muslims.
Maiduguri is the capital of Borno state where Boko Haram first launched its uprising in 2009, beginning with drive-by shootings of policeman but quickly developing the scale and sophistication of its attacks.
Tuesday is public holiday in Nigeria when millions of Muslims are marking the Prophet Mohammad's birthday.
Boko Haram and splinter Islamist groups are viewed as the biggest security threat in Nigeria, Africa's second largest economy.
The United States and its allies are increasingly concerned that Islamist groups in Nigeria will strengthen ties with al Qaeda's north African wing and its largely domestic insurgency could become more anti-Western.
A Boko Haram suicide attack on the United Nations building in 2011 in the capital Abuja killed at least 25 people.
(Additional reporting by Isaac Abrak in Kaduna; Writing by Joe Brock; Editing by Andrew Heavens)