A fifth day of ethnic violence in Pakistan's southeastern Sind province left 30 people dead, including 15 killed in a bus ambush in Karachi, and apparently prompted Prime Minister Benazir Bhutto to cancel a foreign trip.
Authorities kept a curfew in force for the fourth straight day in Hyderabad, where security forces opened fire last Sunday on a crowd of ethnic Mohajir women protesters, killing an estimated 70 people and touching off a violent round of revenge attacks.
Parts of Karachi also were under curfew Thursday and soldiers patrolled the streets in both cities in an effort to prevent clashes between the ethnic Mohajirs, who settled in Pakistan at the time it achieved independence from India in 1947, and natives of Sind province.
More than 170 people have been killed in the latest round of ethnic strife. Bhutto, a native of Sind, traveled to the province Wednesday and issued an emotional appeal for calm.
The prime minister Thursday indefinitely postponed a trip to four Middle Eastern countries that was scheduled to start Saturday, apparently because of the conflict in Sind province, and she consulted throughout the day with the chief minister of Sind, Shaban Mirani.
Thursday's worst incident came about 7 p.m. when gunmen opened fire on a city bus carrying passengers from downtown Karachi to one of the suburbs. Hospital sources said 15 people were killed in the incident and 35 were wounded.
Fifteen other people were slain during Thursday's violence, most of them shot by snipers active in the city.