The death toll in a horrific bombing in a Sufi shrine in Pakistan's Balochistan province rose to 52 on Sunday, with the Islamic State claiming responsibility, the media reported.
Women and children were among the dead, officials said, adding that around 100 others were maimed in the gruesome attack.
Authorities fear the toll might go up further.
The teenage bomber targeted a crowd of devotees performing 'dhamaal' (devotional dance) at the shrine of Sufi saint Shah Noorani, some 750 km south of provincial capital Quetta.
"The bomber appeared to be 14 to 16 years old," a media report quoted a local official as saying.
Dawn quoted police officer Jafar Khan as saying that around 1,000 devotees were at the shrine when the bomber detonated the explosives strapped to his body.
"Every day at sunset, there is a 'dhamaal' session," one witness said.
Chief military spokesperson Lt. Gen. Asim Saleem Bajwa said troops and medical teams were dispatched but "difficult terrain and long distance" were hampering their progress.
Federal Minister for Ports and Shipping Mir Hasil Khan Bizenjo said the suicide bombing could be a reprisal for the killing of a senior commander of a banned militant organisation.
Jundullah chief Saqib, alias Arif alias Anjum Abbas, was killed in a gunfight with security forces on Friday. His wife and nine-year-old son were also injured in the clash.
The carnage came a day before prime minister Nawaz Sharif was to flag off the first shipment of trade goods from Gwadar port to international markets, marking the historic launch of trade activity through the China-Pakistan economic corridor.
Home Minister Sarfraz Bugti said the Balochistan government had no helicopters to ferry the casualties.
The Islamic State terrorist group claimed responsibility for the attack via Amaq, its official news agency.
Balochistan, which borders Iran and Afghanistan, is afflicted by Islamist militancy, sectarian violence and a separatist insurgency.
Local militants claiming to work with the IS attacked a police academy in Balochistan last month, killing 61 people.
In August, a suicide bombing at a Quetta hospital claimed by the Islamic State and a faction of the Pakistani Taliban killed 73 people.
