Kolkata, Jan 4 : West Bengal Chief Minister Mamata Banerjee on Saturday said that the attack on Gurdwara Nankana Sahib in Pakistan by a mob is “unacceptable”. “We condemn the incident of violence at Gurdwara Nankana Sahib in Pakistan. This is unacceptable. Humanity comes above all else,” Banerjee tweeted. On Friday, a mob gheraoed the holy shrine of Nankana Sahib, leaving several devotees stranded inside.