The interior minister says three police officers were killed and 70 wounded, while the government has deployed paramilitary troops in Punjab to help manage the situation.

Lars Vilks had been under police protection since his 2007 cartoon of Prophet Muhammad with a dog's body prompted outrage among those who consider depictions of the Muslim prophet deeply offensive or blasphemous.

He says he is accused of seeking to incite others to commit crimes and improper internet use.

Digital humour looks here to stay, and may feature in the run-up to the next general election.