People push a stretcher carrying a victim of a bomb blast to a hospital in Karachi The death toll from a bomb blast that ripped through an illegal gambling den in Pakistan\'s southern port city of Karachi rose to 19, with more than 40 other

people wounded, officials said. It was not yet clear if the explosion, that hit the city\'s largest gambling complex, the Rummy Club, was a criminal act or caused by religious extremists in the teeming violence-plagued city, a senior home ministry official told AFP on Friday. \"Three more people died of their injuries in hospital overnight, bringing the toll to 19,\" the ministry\'s Sharfuddin Memon said, adding that more than 40 people were receiving hospital treatment with three in a critical condition. \"We are investigating if the attack was the result of rivalry between criminal gangs or if some vigilante groups of extremists were involved,\" Memon said. Hospital official Saleem Ahmed confirmed the casualty figures.

The city houses many clandestine gambling dens, which are officially outlawed in the Islamic nation and subject to occasional police raids.Police said the bomb was small, made of two kilogrammes (four pounds) of explosives, but casualties were high because the gambling hall was crowded at the time. Karachi is Pakistan\'s economic hub, home to its stock exchange and a lifeline for a depressed economy wilting under inflation and stagnating foreign investment.

But the sprawling city, with a population of 16 million, is plagued by ethnic and sectarian killings, crime and kidnappings. Karachi is also politically tense and steeped in rivalries between the Urdu-speaking majority and an influx of ethnic Pashtuns from the northwest, which has been hit by a Taliban insurgency. Outbreaks of political violence there killed more than 150 people last year and extremists targeted Shiite and Sufi religious gatherings, although attacks on government security forces in Karachi have been rare. More than 40 people were killed over 18 days in March, officials said, amid heightened tensions between the Muttahida Qaumi Movement (MQM), which represents Urdu-speakers originally from India, and the Awami National Party (ANP), backed by Pashto-speakers. The MQM and the ANP are partners in the Pakistan People\'s Party-led coalition that rules the southern province of Sindh, of which Karachi is the capital. The violence came just a few hours after Pakistan\'s army had vowed to defeat terrorism and rejected US accusations of Islamabad \"not doing enough\" to combat Islamic militants in its northwest tribal belt.

In another part of this restive country a US drone attack kills several  in North Waziristan,   the most notorious Afghan Taliban and Al-Qaeda bastion in Pakistan. The toll from the attack on a building used by militants  has risen to at least 20 dead, according to a security official in Peshawar.It was the first missile strike to hit the North Waziristan tribal district since March 17 when a drone attack killed 39 people, including many civilians, causing a diplomatic furore over the unpopular US campaign.

\"US drones fired five missiles on a compound in Spinwam, 40 kilometres (25 miles) northeast of Miranshah,\" said a local intelligence official early Friday. Miranshah is the main town in North Waziristan tribal district.\"Several people were also wounded in the attack, which took place at around 4:30 am (2030 GMT),\" he added. A security official in Peshawar said separately that the drones fired five missiles at a house, killing a number of people.

Last month\'s drone attack in the same area led civilian and military leaders to publicly protest the civilian casualties, although the drone campaign is believed to operate with the tacit consent of the government. Islamabad offered compensation to the families of the 39 victims and called the US ambassador to the foreign ministry to formally protest the incident.
The strikes have inflamed anti-US feeling, which is already running high after the January killing of two Pakistani men in a busy Lahore street by a US embassy official later revealed to be working for the CIA.

Meanwhile, sixteen members of Pakistan\'s paramilitary forces were killed in Taliban attacks on a checkpost being set up on the country\'s northwestern frontier, according to a military official. He said 200 armed militants had surrounded the post in the Kharkai area of Lower Dir, an area bordering Afghanistan\'s insurgent-hit Nuristan province.He said 14 of the security forces died in the ambush on Thursday, and a further two were killed in a subsequent attack on troops later sent to reinforce the position.

In the first attack, \"fourteen people were killed including nine Frontier Corps soldiers and five police officials,\" the official said, adding that five or six other members of the security forces were wounded. Local police official Saleem Marwat told AFP that dozens of militants had seized control of the post on Thursday afternoon for the second time, after troops had managed to recapture their outpost overnight.