Churches in Pakistan are tightening their security over fears of the fallout from the Taliban's return to power in neighbouring Afghanistan.

More armed guards have been posted outside churches during Sunday services, which have been targeted by Islamist extremists in the past. 

With the Taliban back in power in Afghanistan, Pakistan's Christians fear an increase in terror attacks. 

Other steps to protect churches include increased surveillance, identity checking, and swiping people with metal detectors before they enter the building for services.

Pakistani human rights activist Sajid Christopher told Aid to the Church in Need (ACN) that militant organisations like the Taliban-linked group may capitalise on recent events in Afghanistan by going after Christians and other religious minorities.

"When the Taliban were in power before, there were a lot of terrorist attacks in Pakistan," he said. 

"There were terrorist organisations attacking churches and other Christian institutes and other Christian institutes. They clearly became targets.

"Now the Taliban are back, it will strengthen the TTP and other Islamist groups and so there could be attacks."

There have been disturbing reports from Afghanistan of Taliban fighters going door-to-door hunting down Christians, other minorities and anyone believed to be associated with the West. 

Mr Christopher added, "Among peaceful and progressive [Muslim] communities there will also be fear but those with a militant mind-set are happy that the Taliban are back in power again."