The death toll has risen to four in the powerful explosion which ripped through a mosque ahead of Friday prayers in Pakistan's restive Balochistan province as another injured person succumbed to his injuries on Saturday, officials said.
As many as 28 people have been injured in the blast.
The explosion, triggered through an Improvised Explosive Device (IED), targeted the Rehmania Mosque in Pashtunabad area of the provincial capital Quetta, police said.
Geo news reported that one of the inured persons died on Saturday.
No group has claimed responsibility of the attack.
Three persons, including a prayer leader, were killed in the blast and 29 other worshippers injured, Balochistan Deputy Inspector General of Police Abdul Razzaq Cheema said, adding the blast occurred just before the Friday prayers started.
The injured were shifted to Civil Hospital Quetta.
President Dr Arif Alvi and Prime Minister Imran Khan condemned the terrorist attack in Quetta.
Alvi expressed deep grief and sorrow over the loss of precious lives and prayed for the early recuperation of those injured in the incident.
Prime Minister Khan directed the authorities concerned to provide best medical treatment facilities to them.
A security official said that the death toll could rise as it was a powerful explosion.
Balochistan Chief Minister Jam Kamal Khan Alyani condemned the blast and summoned a report on the incident. He expressed grief over the deaths and multiple injuries caused by the blast.
The blast came days after terrorists attacked the Pearl Continental luxury hotel in the port city of Gwadar in Balochistan, killing at least eight persons, including four civilians and a Pakistan Navy soldier.
Balochistan, which borders Afghanistan and Iran, is Pakistan's largest and poorest province, rife with ethnic, sectarian and separatist insurgencies.
At least 20 people were killed and 48 others injured last month in a blast at a fruit and vegetable market in Quetta’s Hazarganji area. The attack was claimed by the ISIS terror group.
On April 18, unidentified gunmen donning uniforms of paramilitary soldiers massacred at least 14 passengers, including Pakistan Navy personnel, after forcing them to disembark from buses on a highway in Balochistan.
China is investing heavily in Balochistan under the USD 60 billion China-Pakistan Economic Corridor (CPEC).
The CPEC, launched in 2015, is a planned network of roads, railways and energy projects linking China's resource-rich Xinjiang Uyghur Autonomous Region with Pakistan's strategic Gwadar Port on the Arabian Sea.