Islamabad, Nov 5 (IANS/EFE): Police have detained 43 people involved in the murder of a Christian couple by a Muslim mob for allegedly desecrating the Koran in Pakistan, a police source told Efe news agency Wednesday.

The detainees were residents of Kot Rasha Kishan town in Punjab province where the couple was killed in a bricks factory and their bodies burnt in an oven Tuesday, police spokesperson Bin Yameen said.

The police are searching for the factory manager for his alleged involvement in the killings.

Pakistan's controversial and ambiguous anti-blasphemy legislation punishes any disrespect towards sacred Islamic symbols, but it is often applied arbitrarily and on the basis of third-party testimony.

The norm came into force during the British colonial period to curb religious clashes, but the reforms introduced in the 1980s by Zia-ul-Haq encouraged the extremists to abuse the law.

The continuous strengthening of legislation and radicalisation of the country since the 1980s has sparked accusations of blasphemy and extrajudicial executions of alleged blasphemers, usually belonging to religious minorities.