A strike in favour of Pakistan's controversial blasphemy laws has led businesses to shut down and buses to stay off the streets in many parts of the Muslim country.

The law gained new attention when a Christian woman, Asia Bibi, was sentenced to death in November for allegedly insulting the Prophet Muhammad.

Islamist groups called for the strike despite assurances by the ruling party that it would not change the law.

Outside mosques in Karachi city, large numbers of men rallied in favour of the regulations after Friday prayers.

Rights groups say the law is abused by people to settle grudges or target religious minorities.

Most people accused of blasphemy eventually have their sentences thrown out. No one has been executed under the regulation.