Cold weather has killed 17 people in camps for internally displaced people in Afghanistan so far this month.
In a statement, Amnesty International said the casualties included 11 children and occurred in camps in the western city of Herat and the capital, Kabul.
Amnesty's Deputy Asia-Pacific Director Polly Truscott says the "deaths were a preventable tragedy."
She says hundreds of thousands of displaced Afghans receive inadequate winter assistance.
Afghan officials, however, say they have received reports of only two deaths.
Aid workers say some 100 Afghans, mostly children, were killed by cold weather last winter.
Fighting between the government and insurgents has forced 500,000 Afghans to live in displacement camps.
Aid organizations estimate more than 2 million Afghans are threatened by extreme cold this winter.
Based on reporting by dpa, AFP, and RFE/RL's Radio Free Afghanistan