JOS, Nigeria (Reuters) - Islamist sect Boko Haram claimed responsibility on Tuesday for attacks that killed more than 65 people in volatile central Nigeria last weekend, although security forces have blamed the violence on localized ethnic clashes.
Boko Haram has killed hundreds of people this year in an insurgency against President Goodluck Jonathan as it tries to carve out an Islamic state in Africa's most populous nation.
"We praise God in this war for the Prophet Mohammad. We thank Allah for the successful attack in ... Plateau state on Christians and security men," an email in the local Hausa language from the Boko Haram's spokesman Abul Qaqa said.
The email was sent to reporters in Boko Haram's home base in northeast Maiduguri from an address previously used by Qaqa.
But there were doubts about the level of Boko Haram's involvement.
Security forces said fighting which erupted on Saturday involved nomadic Fulani herdsmen who often clash with indigenous tribes in the unstable "Middle Belt", where the largely Muslim north meets the mostly Christian south.
On Sunday, gunmen shot dead a senator and several other people at a mass burial of at least 63 people killed in the violence.
"Before, Christians were killing Muslims, helped by the government, so we have decided that we will continue to hunt down government agents wherever they are," Qaqa's email said. Boko Haram has often targeted government officials.
Security forces did not comment on the claim of responsibility.
But Fulani herdsmen said there was no link between them and Boko Haram, which has been behind several suicide bombings on churches in Plateau state this year.
"Boko Haram did not play any role here," said Mohammed Nura, executive secretary of the Miyetti Allah Breeders Association of Nigeria, who represent the Fulani. He added that Fulanis were not behind the attack on the funeral.
President Jonathan, who sacked his defense minister and national security adviser last month, pledged to track down the people who killed Senator Gyang Dantong, of the ruling People's Democratic Party.
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.
Security experts believe Boko Haram's attacks on churches in central and northern Nigeria are an attempt to provoke a wider religious conflict inside Africa's biggest oil producer.
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, which launched its first uprising in remote northeast Nigeria in 2009, has linked up with al Qaeda in the Islamic Maghreb (AQIM), sending a few dozen fighters to Mali for training.
(Additional reporting by Ibrahim Mshelizza in Maiduguri, Isaac Abrak in Lagos, Augustine Madu in Kano, Mike Oboh and Afolabi Sotunde in Abuja; Writing by Joe Brock; Editing by Matthew Tostevin)
This stroy was corrected to fix the name of Fulani group attributed to the quote in eleventh paragraph