Police say at least 39 people have been killed in political and ethnic violence in Pakistan's southern port city of Karachi in the last three days.
Gunmen opened fire on buses Thursday in the latest unrest.
Police blame clashes between rival political groups in Sindh province, the Muttahida Qaumi Movement (MQM) and the Awami National Party (ANP).
The MQM largely represents the Urdu-speaking community, and until last month was part of the ruling coalition in Sindh. ANP represents ethnic Pashtuns.
MQM leader Raza Haroon on Thursday threatened a city-wide strike and said provincial lawmakers would rally Friday to protest the government's inaction to quell the violence. He said MQM supporters were being targeted because the party quit the coalition.
Additional police and paramilitary personnel have been deployed in the city to try and quell the latest surge in political violence.
Some 16 million people live in Pakistan's economic hub of Karachi. The city has also been the scene of sectarian violence between Sunni and Shi'ite Muslims and militant attacks.
Article by VOA News