By Ibrahim Mshelizza
MAIDUGURI, Nigeria (Reuters) - A bomb blast struck a police commissioner's convoy in the eastern Nigerian town of Jalingo on Monday, killing seven people and wounding 20, a witness and officials said, a day after two deadly attacks in other parts of the country.
No group immediately claimed responsibility but Islamist sect Boko Haram, which wants to carve an Islamic state out of Nigeria, has been blamed for many such previous attacks.
Jalingo is the capital of usually peaceful Taraba state, which borders Cameroon and has so far been spared the insurgency plaguing Nigeria's north.
"I saw the blast happen. It was apparently targeted at the commissioner of police who was passing the vicinity," Ben Adaji, editor of a local magazine, told Reuters by telephone.
"The motorcycle outrider on the commissioner's convoy is among the seven people I saw dead."
The local head of the National Emergency Management Agency (NEMA) said 20 people had been taken to hospital. The blast happened between the state ministry of finance and police headquarters, Ibrahim Farinloye said.
In the past year, Boko Haram has tried to extend its reach beyond its northeastern heartland. The Jalingo strike followed two attacks on Christian worshippers on Sunday that killed at least 19 people in other parts of the country.
Gunmen attacked a university theatre used for services in the northern city of Kano and a church in northeast Maiduguri, Boko Haram's hometown.
The sect's attacks usually target police and government in the mostly Muslim north but it also frequently strikes Christian targets in the capital Abuja.
Jonathan has been criticized for failing to get a grip on the violence, which has gained momentum since his presidential election victory a year ago.
He has relied mostly on a heavy-handed military approach to dealing with the violence and an attempt at mediated dialogue with the sect broke off last month.
Suicide car bombers targeted the offices of Nigerian newspaper This Day in Abuja and in Kaduna last week, killing at least four people in coordinated strikes.
"The President urges Nigerians to remain united in their condemnation and rejection of the terrorists who have shown even more clearly by their latest attacks on the media and the academic community that their objective is to destabilize the nation," a presidency statement said on Monday.
Africa's most populous nation of more than 160 million is split roughly equally between a largely Christian south and a mostly Muslim north.
(Additional reporting and writing by Joe Brock; Editing by Tim Cocks and Angus MacSwan)