Suicide bombers in Pakistan killed at least 57 people and wounded nearly 200 in a blast Friday night.
The two bombers blew themselves up in a busy market in the Shia town of Parachinar in what appeared to be a sectarian attack.
All of the dead and wounded were Shia Muslims.
The market was full of people buying food for the evening meal to break the Ramadan fast - known as iftar. The bodies and injuries overwhelmed the city's tiny hospital.
Dawn reported that the attack was carried out by an upstart Islamic militant group calling themselves Ansarul Mujahideen. It was reportedly their first attack outside Waziristan
The group said it was formed to respond to US drone strikes, saying that with each drone attack we will respond by a new suicide attack.
Dawn said that recent suicide bombings at army checkpoints in Pakistan were the work of the group in retaliation for drone attacks by the US.
Pakistanis are angry at their government for not doing more to halt the strikes. It is believed the CIA has cut down the number of strikes partly due to public rage in Pakistan.
The government has said that drone strikes are counter-productive and violate the country's sovereignty.
Parachinar is near the tribal area of Kurram on the Afghan border.