* Bomber was a teenage boy - deputy state governor
* Islamist Boko Haram began insurgency in Maiduguri
* Sect often targets government, religious figures (Adds background, quote, bullet points)
By Ibrahim Mshelizza
MAIDUGURI, Nigeria, July 13 (Reuters) - A suicide bomber killed five people at the central mosque in the northeastern Nigerian city of Maiduguri on Friday, the military said, the latest attack in a region plagued by Islamist Boko Haram insurgents.
The blast narrowly missed the deputy governor of Borno state, Zanna Umar Mustapha, and Borno's Shehu (regional religious leader), Abubakar Umar Garbai El-Kanemi, who were attending Friday prayers.
"The suicide bomber was about 15 years old ... Fortunately we both escaped unhurt," Mustapha told reporters.
Six people were also injured in the attack, military spokesman Sagir Musa told reporters.
Boko Haram has killed hundreds of people this year in an insurgency against President Goodluck Jonathan, seeking to carve out an Islamic state in Africa's most populous country and biggest oil producer.
The sect often targets government officials, religious figures and places of worship, usually Christian churches.
Security experts believe Boko Haram's attacks on religious centres in central and northern Nigeria are an attempt to provoke wider religious conflict in the country.
Boko Haram claimed responsibility for attacks that killed more than 65 people in volatile central Nigeria over the weekend, including a ruling party senator, although security officials blamed localised ethnic clashes.
The attacks in Nigeria's "Middle Belt", where the largely Christian south meets the mostly Muslim north, would be a new development in the sect's insurgency and its greatest effort yet to divide the country along religious lines.
Jonathan, a southern Christian, has come under intense pressure to stem the spread of violence in the north, where his opponents say he is out of touch.
He sacked his defence minister and national security adviser last month, pledging to introduce new tactics to fight "terrorism" but gave no details.
Critics say Jonathan's heavy-handed military approach has aggravated the violence and there have been calls for him to engage with northern power brokers, although Boko Haram has said several times it is not interested in dialogue.
"We don't know what to do now because we thought our call for dialogue would work but as you can see we have to think of other ways," Borno Deputy Governor Mustapha said.
Boko Haram first launched an uprising in 2009 but a military crackdown stemmed the violence.
The group revived its insurgency in early 2010, hitting military and government targets in and around Maiduguri.
Since Jonathan's election victory in April last year the sect's violence has escalated and spread with attacks, including several suicide bombings, in major cities across the north and the capital Abuja.
The United States last month named three alleged leaders of Boko Haram as "foreign terrorists", the first time it has blacklisted members of the sect.
Security sources say the sect has linked up with al Qaeda in the Islamic Maghreb, sending a few dozen fighters to Mali for training. (Writing by Joe Brock; Editing by Andrew Heavens)