* Christian youths kill at least two in reprisal killings
* Attacker drove jeep into packed Catholic church
* Islamist sect Boko Haram has claimed such attacks in past (Updates death toll)
By Garba Mohammed and Isaac Abrak
KADUNA, Oct 28 (Reuters) - A suicide bomber drove a jeep packed with explosives into a Catholic church in northern Nigeria on Sunday, killing at least eight people, injuring more than 100 and triggering reprisal attacks that killed at least two more, officials said.
The bomber drove right into the packed St Rita's church in the Malali area of Kaduna, a volatile ethnically and religiously mixed city, in the morning, witnesses said.
A spokesman for the National Emergency Management Agency (NEMA) Yushua Shuaib said eight people had been confirmed killed and more than 100 injured.
There was no immediate claim of responsibility but Islamist sect Boko Haram has claimed similar attacks in the past and has attacked several churches with bombs and guns as it intensified its campaign against Christians in the past year.
"The heavy explosion also damaged so many buildings around the area," said survivor Linus Lighthouse.
A wall of the church was blasted open and scorched black, with debris lying around. Police cordoned the area off.
Church attacks often target Nigeria's middle belt, where its largely Christian south and mostly Muslim north meet and where sectarian tensions run high. Kaduna's mixed population lies along that faultline.
Shortly after the blast, angry Christian youths took to the streets armed with sticks and knives. A Reuters reporter saw two bodies at the roadside lying in pools of blood.
"We killed them and we'll do more," shouted a youth, with blood on his shirt, before police chased him and others away. Police set up roadblocks and patrols across the town in an effort to prevent the violence spreading.
At least 2,800 people have died in fighting since Boko Haram's insurrection began in 2009, according to Human Rights Watch. Most were Muslims in the northeast of the country, where the sect usually attacks politicians and security forces.
The sect says it is fighting to create an Islamic state in Nigeria, whose 160 million people are split roughly evenly between Christians and Muslims.
Another witness to the bombing, Daniel Kazah, a member of the Catholic cadets at the church, said he had seen three bodies on the bloodied church floor in the aftermath.
In previous such attacks, bombers have usually failed to enter church buildings and detonated their explosives at entrances or in car parks.
A spokesman for St Gerard's Catholic hospital, Sunday John, said the hospital was treating 14 injured. Another hospital, Garkura, had at least 84 victims, a NEMA official said.
Many residents of Kaduna rushed indoors, fearing an upsurge in the sectarian killing that has periodically blighted the city. A bomb attack in a church in Kaduna state in June triggered a week of tit-for-tat violence that killed at least 90 people. (Writing by Tim Cocks; Editing by Andrew Roche)