Police in Pakistan say at least 45 people have been killed in the country's commercial capital of Karachi since Monday's assassination of a senior leader of the city's dominant political party.
The slain politician, Raza Haider, was a provincial lawmaker and belonged to the Muttahida Quami Movement or MQM political party. He was attending a funeral in Karachi late on Monday when unknown gunmen riding motorcycles attacked and killed the lawmaker along with his bodyguard.
Police say an outbreak of violence following the deadly attack left dozens of people dead and scores of others wounded. Angry protesters also set fire to a number of vehicles and private and government properties across Karachi.
Authorities deployed paramilitary forces to help police bring the situation under control, but there was no let-up in the violence throughout the night. The tense city was shuttered by the violence on Tuesday. Traffic was very thin as schools were closed and business activity halted in Pakistan's largest city.
Known as the lifeline of the country's economy, Karachi is home to the main port, stock exchange and the central bank.
Who is to blame?
In Islamabad, Federal Interior Minister Rehman Malik told lawmakers that the assassination of the politician in Karachi could be the work of Taliban-linked militants. Malik said they have received information that a network of Taliban and other militant groups, including Sunni militant Sipah-e-Sahab Pakistan, is trying to fuel political tensions by carrying out such attacks. He said that police have detained more than 20 people in connection with the violence.
But leaders of the MQM, which represents the city's majority Urdu-speaking community, blamed the attack on a rival political force, the Awami National Party, or ANP, which is a representative of Karachi 's ethnic Pashtun population.
The two major political forces have routinely blamed each other for deadly attacks on their activists. Politically motivated violence so far this year alone has left nearly 200 people dead in Karachi.
Both the MQM and the ANP are part of the ruling coalition in the federal government led by the Pakistan Peoples Party or PPP.
Cause and effect
Critics say that the latest outbreak of violence in the city has exposed the helplessness of the government to perform its basic duty to protect its citizens. Qazi Ahmed Kamal, a representative of Karachi 's textile chemical industry, said ordinary Pakistanis are paying the price for the government's inability to control outbursts of violence.
"The saddest part of the whole scenario is that it is the citizens who bear everything. They bear the emotional stress. They bear the financial loses, and they also bear the loss of hope of anything going better than it is going today from the government side." said Kamal.
Pakistani officials also blame criminals, including drug lords for the unrest in Karachi, saying these elements take advantage of the political tension in the city, making it difficult for the police to go after the real culprits.