KARACHI, Pakistan -- Pakistani forces regained control Saturday over trouble spots in the nation's largest city where five days of political and ethnic violence killed at least 93 people and forced many to stay at home in fear, an official said.
The fighting in Karachi, a sprawling southern port city of 18 million people, has added to the instability in this nuclear-armed, U.S.-allied nation, which is already bedeviled by Islamist militancy.
Karachi occasionally erupts in violence, often due to various ethnic, political and sectarian tensions. But the latest spell has been extraordinary even by this chaotic city's standards.
It follows the decision by the city's most powerful political party, the Muttahida Qaumi Movement, to leave the federal ruling coalition and join the opposition. Such moves by the MQM have traditionally been accompanied by outbursts of fighting.
Senior police official Saood Mirza said Saturday that more than 150 people were detained on suspicion of a role in the gunfights in various neighborhoods.
By early evening Saturday, a spokesman for the paramilitary Rangers said the violence was under "complete control."
"The Rangers have completely taken over the affected areas and the miscreants have been swept out," Maj. Farooq Bilal said.
The violence in parts of the metropolis got so bad that security forces were ordered to shoot gunmen on sight Friday.
Karachi routinely witnesses more 1,000 violent deaths a year, but officials say crime here has risen as Al Qaeda and Taliban-led militancy has spread in Pakistan. Karachi's misfortune adds to the nation's troubles because it is the country's primary business center, and the economy of Pakistan is already struggling.
According to the Human Rights Commission of Pakistan, 1,138 people have been killed in Karachi in the first six months of this year, a figure that doesn't include this week's toll. Of the Commission's figure, 490 were victims of so-called targeted killings, which are often linked to political, ethnic and sectarian groups.
Many of the killings that began Tuesday appeared linked to political and ethnic turf battles, officials said. Some of Karachi's leading political parties have been formed along ethnic lines, though all deny targeting one another's activists.
MQM dominates Karachi politics, but over time it has seen challenges to its power as an influx of ethnic Pashtun residents have moved to the city and given a boost to the rival Awami National Party, a Pashtun nationalist party.
Also in the mix is the Pakistan People's Party, which is ruling party on the federal level as well as in the province of Sindh. All three parties were partners in the federal ruling coalition until late June, when the MQM said it would join the opposition.
Late Friday, Pakistani President Asif Ali Zardari, Prime Minister Yousuf Raza Gilani and other top officials met to discuss the Karachi violence. Afterward, they announced they would support making changes to the system of local government in the Karachi area to make authorities more responsive to crises.
However, it is unclear whether some of their proposed changes, such as bringing back a system of appointed commissioners, will appease the MQM, which prefers to have an elected system of local leaders that is more likely to give it additional influence in the city.
U.S. Ambassador to Pakistan Cameron Munter also expressed deep concern over the escalating violence. In a statement on Friday, he called "on all parties to refrain from further violence and work toward a peaceful resolution of differences."
Interior Minister Rehman Malik said those behind the attacks were ultimately helping the Taliban, who want "mass killings" and "destabilization."
The U.S. has a keen interest in keeping Pakistan stable -- it needs the country to stay focused on fighting Taliban and other Islamist militants, some of who threaten Western troops across the border in Afghanistan. But Pakistan has for the most part taken action only against militants who stage attacks on its soil.
Late Friday, a Pakistani warlord who has focused on fighting U.S. and NATO troops in Afghanistan condemned militants who carry out attacks on Pakistani soil. Hafiz Gul Bahadur's statement illustrates the splintered nature of the Islamist militant movement in Pakistan.
Because Bahadur's fighters don't go after Pakistani targets, the Pakistani military has largely left him alone. However, his territory in the North Waziristan tribal region has come under attack by drone-fired U.S. missiles.
Earlier this week, an army convoy was struck by a roadside bomb in North Waziristan. That prompted the army to retaliate, including destroying a hospital where the suspected militants behind the bombing were believed to be hiding, intelligence officials said.
As soldiers were attacking the hospital, they took heavy fire from militants in the Miran Shah bazaar and eventually had to call in helicopter gunships for support, said the officials, who spoke on condition of anonymity because they were not authorized to speak on the record to media.
Bahadur warned that his fighters would pursue militants behind such acts, saying they must be American agents.
"We give a go-ahead to all commanders in Waziristan, mujahideen and people to kill such criminals who come to do such acts again in populated areas, houses or hotels, and we will take responsibility for that," said his statement, issued after he met a group of like-minded militant leaders.