A mob killed a man and wounded three others over the alleged desecration of a Koran in the southwestern Pakistani city of Quetta on Wednesday, officials said.
The violence started when some vendors allegedly found torn-out pages of Koran in a pomegranate crate they received in a shipment from neighbouring Iran, witnesses and officials said.
A mob then formed, shouting slogans against Shiites, who form a majority in Iran.
They destroyed shops, burnt a motorcycle and tried to march towards a Shiite neighbourhood in the city but were stopped by police, a senior police official told AFP on condition of anonymity.
The crowd began shooting indiscriminately in various parts of the city, which resulted in one death and bullet wounds to three others.
"At least one man was killed and three others were wounded in firing incidents in the city," provincial home secretary Asad Gilani told AFP.
Gilani said the unrest in the city was contained after paramilitary troops were deployed in key areas, but he declined to shed light on the allegations of desecration.
He said that nobody had come to the police to register a case under the country's strict blasphemy law.
In June last year a man was killed and 19 others were wounded when a mob attacked a police station demanding a man detained for allegedly desecrating the Koran be handed over.
Pakistan is majority Sunni Muslim and its tough anti-blasphemy laws make defaming Islam or the Prophet Mohammed, or desecrating the Koran, punishable by death.
Quetta is the capital of restive Baluchistan province which suffers regular violence from Islamist insurgents, separatist rebels and sectarian militants.