JOHANNESBURG: UN chief Ban Ki-moon has condemned recent attacks by Islamic militants that killed hundreds of people in Nigeria, which holds elections next month even though Boko Haram extremists hold large swaths of territory in the northeast of Africa's most populous country.

Ban's office said in a statement Sunday that the secretary-general was appalled by reports that hundreds of civilians were slaughtered in an assault around Baga town in Borno state, near Nigeria's border with Chad.

Some reports say the death toll is as high as 2,000.

An Amnesty International statement had said there are reports that the Baga town was razed and as many as 2,000 people killed.

Take a look: Nigeria massacre deadliest in history of Boko Haram: Amnesty

If true, “this marks a disturbing and bloody escalation of Boko Haram's ongoing onslaught,” Daniel Eyre, Nigeria researcher for Amnesty International, had said.

In Washington, US State Department Spokesman Jen Psaki had also condemned the attacks.