Lahore: A woman and her two minor grand-daughters were killed when an angry mob set alight several houses, shops in Pakistan's Punjab province belonging to the minority Ahmadi sect in riots that followed the alleged posting of blasphemous content on Facebook.

The violence erupted yesterday in the city of Gujranwala, about 80 kilometres from Lahore, after claims that a Ahmadi youth, 17, ad posted a photo containing blasphemous content, said Amir Mahmood, an office-bearer of the Ahmadi community.