The Islamic State group has claimed responsibility for the attack and for several other attacks in Baluchistan in recent years.
About 400 worshippers were attending the service when two bombers carrying assault rifles stormed the church, triggering a gunbattle in which one assailant was killed by police guards and the other opened fire at worshippers and detonated his explosive vest. The deadliest example was in September 2013, when twin suicide bomb blasts killed 85 people in a Peshawar church.
Talking to media on Sunday, Balochistan Inspector General (IG) Moazzam Ansari said there were around 400 people present in the church at time of the attack but a tragedy was thwarted owing to a timely action by security personnel. "Unfortunately one terrorist blew himself up which resulted in the loss of life", he told the reporters, Reuters reported.
They exploded a suicide vest and shot at Christian worshippers before one of them blew himself up and police killed the other.
Another police official, Abdur Razaq Cheema, said two other attackers escaped.
"It was a coordinated attack", he said, adding that the security forces have cleared the church.
Hospital officials said two women were among the dead while another five women and two children were among the wounded.
Bugti said law enforcement agencies took about 16 minutes to complete their operation.
The minister said training programs are being launched to strengthen police and that there is a need to boost morale of the forces in order to get fruitful outcomes. No group has yet claimed responsibility for the attack.
Army chief Gen Qamar Javed Bajwa condemned the attack, calling it "an attempt to cloud Christmas celebrations/create religious cleavages". Some officials were quick to shift blame toward Afghanistan, pointing to the presence of havens there for militants.
A young girl in a white dress sobbed as she recounted the attack to Geo television, saying many people around her were wounded.