At least 35 people have been killed and 60 hurt in an explosion at a Pakistan-India border town, officials say.
The explosion happened near the famous Wagah border crossing between the two countries.
At least 15 of those injured are seriously wounded, local police told the BBC.
Huge crowds gather every day at the crossing to watch a "lowering of the flags" ceremony, which soldiers from both sides have conducted for decades.
Pakistani authorities are examining the possibility that a suicide bomber was behind the attack, police told the BBC.
Reports also suggest that the cause of the explosion may have been a cylinder blast, but there is no confirmation.
Security and rescue personnel have rushed to the site of the blast. The injured have been rushed to hospital.
Emergency has been declared at all hospitals in Lahore. Prime Nawaz Sharif has taken notice of the explosion and called for a report on the incident.
Wagah is the only road border crossing between the Indian city of Amritsar and the Pakistani city of Lahore.
