The UN Security Council has approved sanctions against the Nigerian militant group Boko Haram, five weeks after it kidnapped more than 200 schoolgirls, BBC News reported.

It will now be added to a list of al Qaeda-linked organizations subject to an arms embargo and asset freeze.

U.S. envoy Samantha Power said it was an "important step" in support of efforts to "defeat Boko Haram and hold its murderous leadership accountable".

It was earlier blamed for the deaths of 27 people in a north-eastern village.

Residents said gunmen had shot dead farm workers in Chikongudo, set fire to nearly all the homes there and stolen food in an attack on Wednesday, May 21 night. The assailants stormed the village in cars and motorbikes, a trademark of Boko Haram, the residents added.

It came a day after twin bombings killed 122 in the central city of Jos. The authorities suspect Boko Haram of being behind them, but there has so far been no claim of responsibility from the group.

Boko Haram was added to the al Qaeda Sanctions Committee's list of designated entities on Thursday at the request of Nigeria.

"Today, the Security Council took an important step in support of the government of Nigeria's efforts to defeat Boko Haram and hold its murderous leadership accountable for atrocities," Power said.

The sanctions designation would help "close off important avenues of funding, travel and weapons" to the group, she added.

Reports quoting a draft UN document said its members had received training from al-Qaeda affiliates and fought alongside them in Mali.

Boko Haram, which has killed thousands of people in Nigeria through a wave of bombings and assassinations since 2009, is fighting to overthrow the government and create an Islamic state.

The government's failure to prevent attacks since launching an offensive against Boko Haram a year ago has triggered widespread anger.