At least 52 people have died and dozens more injured in an explosion in southwest Pakistan, police said.
The suspected suicide bombing attack occurred outside a mosque in Mastung, a district in Baluchistan province, authorities said.
The injured have been taken to nearby hospitals, government administrator Attah Ullah said.
Some people were in critical condition and a senior police officer was also among the dead, Ullah said.
"The bomber detonated himself near the vehicle of the Deputy Superintendent of Police," Deputy Inspector General of Police Munir Ahmed told Reuters news agency.
Pakistan's President Arif Alvi has condemned the attack. He asked authorities to provide all possible assistance to the wounded and the victims' families.
No group has claimed responsibility for the attack.
A religious holiday, and an uptick in attacks in the country
Millions of Muslims around the world are celebrating the birthday of Islam's Prophet Muhammad — otherwise known as Mawlid al-Nabi.
Believers may go to mosques to pray and read the Quran or hold public festivities to celebrate the life of the prophet.
In a statement, caretaker Interior Minister Sarfraz Bugti denounced the bombing and expressed sorrow over the loss of lives, saying it was a "heinous act" to target people on Mawlid al-Nabi.
Balochistan, which borders Afghanistan and Iran, is the largest and least-populous province in Pakistan.
Ethnic separatist groups including the Balochistan Liberation Army have long waged a low-level insurgency against the Pakistani government. Pakistani Taliban also have a strong presence in the province.
The country has seen an increasing number of attacks this year, especially by Islamist militants, following the breakdown of a cease-fire agreement between the Pakistani Taliban and the national government last year.