Violence blamed on political and ethnic tensions in Pakistan\'s biggest city Karachi has killed 33 people in consecutive nights of bloody murders, officials said Thursday. The killings have been blamed on loyalists of former coalition partners the Muttahida Qaumi Movement (MQM) and Awami National Party (ANP), which represent different ethnic communities and straddle volatile political fault-lines. They underscore deep insecurity in the country\'s economic hub used by NATO to ship supplies to Afghanistan. The city is also plagued by sectarian killings, crime and kidnappings. \"We have received reports that another nine people have fallen victim to targeted killings overnight, putting the death toll at 33 in two days,\" said Sharfuddin Memon, a home ministry official in the southern province of Sindh. He said police were hunting those involved and had detained several suspects since Wednesday. A security official said several western neighbourhoods were still tense and sounds of intermittent gunfire could still be heard. Local residents complained they were virtually confined to their homes because of indiscriminate firing. \"Many people here had run out of their food stocks. There is no milk for children and no chance of patients being shifted to hospitals for treatment,\" said Mohammad Asghar, a schoolteacher in the Orangi area. \"We are left at the mercy of trigger-happy scoundrels and the security forces are conspicuous by their absence,\" he added. Memon insisted, however, that police and paramilitary were on patrol in the troubled neighbourhoods. The Human Rights Commission of Pakistan says 490 people have been killed in targeted killings so far this year, compared to 748 in 2010 and 272 in 2009. This week it blamed the government, led by the Pakistan People\'s Party (PPP) of President Asif Ali Zardari, for failing to stop the killings. The MQM recently quit the PPP-led coalitions that rule both Sindh, where Karachi is the capital, and the federal government. ANP is still a partner.