The UN's human rights office on Tuesday condemned the killing of scores of villagers by suspected Boko Haram Islamists in Nigeria, and urged the government to do more to protect civilians.
"We condemn in the strongest terms Sunday's attack by gunmen against eight villages in Adamawa and Borno States, which led to the death of more than 150 people," said Ravina Shamdasani, spokeswoman for the UN high commissioner for human rights.
"We are appalled by the extreme and indiscriminate violence which Nigeria has being witnessing in recent times," she told reporters.
Hundreds of homes have been destroyed and many villagers have fled their communities in fear of further attacks.
Three of Nigeria's northeastern states were placed under emergency rule in May last year, when the military launched a major offensive aimed at crushing the Islamist uprising which has killed thousands since 2009.
Attacks have continued despite the beefed up military presence. Borno state, where Boko Haram was founded in 2002, has been the hardest hit.
The extremist militia has said it is fighting to create a strict Islamic state in the country's mainly Muslim north.
"We urge the government to do more to provide security and protection to civilians, especially in areas prone to attacks and where a state of emergency has been proclaimed," said Shamdasani.
"We also call upon the authorities to launch a prompt and thorough investigation, and make sure that perpetrators of these gross human rights violations and killings are duly prosecuted and held responsible," she added.
On Monday, the governor of Borno state warned Nigeria's President Goodluck Jonathan that the military was being outgunned in its fight against Boko Haram and that more troops were urgently needed.