At least 52 people were killed and dozens more injured in a suicide bombing attack outside a mosque in Mastung, a district in Balochistan province, Pakistan, police said.

Friday's attack came as a large crowd had gathered outside the mosque to celebrate the birthday of the Prophet Muhammad.

Some people were in critical condition and a senior police officer was also among the dead, government administrator Attah Ullah said. 

President Arif Alvi condemned the attack and asked authorities to assist the wounded and the victims' families.

In a separate incident in neighboring Khyber Pakhtunkhwa province, at least five people were killed when two explosions at a mosque.

Islamist militants have attacked both provinces that border Afghanistan in recent years. These militants aim to overthrow Pakistan's government and impose strict Islamic law.

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.

Baluchistan, 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.

lo,rm/ab (Reuters, AP, dpa)