Pakistan police have said violence erupted at a rally convened by Islamists in favour of the country's harsh blasphemy laws in the city of Lahore.
Wednesday's rally coincided with the commemoration for a former governor killed for supporting a Christian woman, Asia Bibi, who has been on death row for years after being accused of blasphemy.
Senior police officer Haider Ashraf said 76 demonstrators were detained as they tried to reach the family residence of Salman Taseer, the ex-governor killed in 2011 by his bodyguard for backing Asia Bibi.
Ashraf said officers used tear gas to disperse the rally.
On Tuesday, one of Taseer's sons, Shan Taseer, angered Islamists by urging people on Twitter to pray for Bibi. Under Pakistan's blasphemy laws, anyone found guilty of insulting Islam can be sentenced to death.
