Tension is running high in the Pakistani province of Punjab after a place of worship belonging to the Ahmedi sect was set on fire late on Sunday night.
The place of worship in Syedwallah about 100 kilometres (62 miles) west of Lahore was attacked while dozens of Ahmedis - including women and children - were listening to a religious sermon broadcast on foreign television.
An Ahmedi spokesman said those inside had to be moved to two private homes because the police warned them that mainstream Sunni Muslims were unhappy about the gathering.
The spokesman said the crowd set fire to the place of worship, completely destroying it.
The crowd then surrounded the houses where the Ahmedi worshippers had gone, staying there for almost four hours chanting slogans.
Arrests
Additional Superintendent of Police Chaudri Ashraf told the BBC that he broadly agreed with the Ahmedi version of events.
But he said Sunni Muslims in the town had complained that they had been verbally abused by the Ahmedis at the place of worship.
The police official said over two dozen Ahmedis had been arrested for their own protection during the incident.
None of the attackers has been taken into custody.
The attack comes less than a year after a series of violent incidents in the Sialkot and Sargodha districts of Pakistan's Punjab province in which at least 10 Ahmedis were killed.
The Pakistani parliament declared Ahmedis heretics more than 25 years ago on the grounds that they believe that the Prophet Muhammad may not be the last prophet.
Ahmedis say they have suffered violence and discriminatory treatment at the hands of mainstream Sunni Muslims ever since.