Police say more than 38 people have been killed in political and ethnic violence in Pakistan's southern port city of Karachi in the last three days.

Authorities say at least 10 of the killings look place late Wednesday.

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.

Additional police and paramilitary personnel have been deployed in Karachi to try and quell the latest surge in political violence.

The Human Rights Commission of Pakistan blames the government for failing to stop the violence.

The city has also been the scene of sectarian violence between Sunni and Shi'ite Muslims and militant attacks.