Pakistani police and paramilitary forces are conducting raids throughout Karachi, after more than 100 people were killed in a week of political and ethnic violence.

Officials said Wednesday that at least 14 people have been arrested in overnight joint operations in Pakistan's largest city. Security forces also confiscated a large number of weapons and ammunition.

The raids come amid mounting calls for the federal government to deploy the army to help quell the escalating violence.

Hundreds of people have been killed in recent months in one of the worst waves of unrest in Karachi in years. Many of the killings are blamed on ethnic gangs linked to rival political factions, such as the majority Urdu-speaking MQM and the mostly ethnic Pashtun Awami National Party.

Pakistani Prime Minister Yousuf Raza Gilani traveled to Karachi on Monday for talks with government officials in Sindh province. The prime minister said that strict action should be taken against those responsible for the violence.

Pakistan's economic hub is home to about 18 million people. Karachi has also been the scene of militant attacks and sectarian violence between Sunni and Shi'ite Muslims.