At least 48 people, including three Pakistani border security personnel, were killed and over 100 others were injured in a suspected suicide bomb attack at Pakistan's Wagah border with India, Anadolu Agency reported referring to police.
Local Pakistani TV channels report that a splinter group of the Pakistani Taliban called Jamaat-ul-Ahrar has claimed responsibility for the attack.
The Wagah border crossing is near Pakistan's second largest metropolitan city Lahore. Every evening, crowds on both sides of the border gather to witness a special lowering of flags ceremony, which border guards on both sides conduct with great pomp and show.
Eyewitnesses say the blast occurred when hundreds of people were disembarking from a pavilion at the end of the traditional ceremony.
"It was a deafening blast that tossed me in the air and threw me meters away," Ghulam Mustafa, an eyewitness told reporters.
"All I remember is a massive blast followed by hue and cry from people," Tahir Ali, who received minor injuries, told reporters at a private hospital.
Charred pieces of human flesh, shoes, clothes and other belongings were strewn all across the blast site. Several ambulances rushed to the site to shift dozens of injured and dead to hospitals.
Major General Tahir Khan, head of Pakistani border security force known as Pakistan Rangers, confirmed the 48 death toll, including three border forces personnel.
Dr Khurram Hussein, an administrator of a private hospital near the blast site, told the media that apart from 48 bodies, nearly 100 people with injuries were brought to the hospital.
Earlier, Punjab police chief Mushatq Sukhera said police had collected ball bearings from the blast site which indicate it was carried out by a suicide bomber.