ISLAMABAD -- The Pakistani army on Thursday rejected what it called "negative propaganda" by the United States, hours after the top U.S. military officer accused the country's spy agency of continued links to a powerful Afghan Taliban faction.
Meanwhile, at least 15 people were killed in a bomb blast inside an illegal gambling den in Pakistan's largest city of Karachi, officials said. The motive for the attack late Thursday was not clear, though a government minister said a criminal gangs, not Islamist extremists, were suspected.
The unusually strident back and forth between the American and Pakistani officials reflected the poor state of relations between the two counterterrorism allies, which sunk to new lows after an American CIA contractor in January shot and killed two Pakistanis he said were trying to rob him.
While officials from both nations have raised the level of rhetoric, they have also spoken of the need to keep the partnership intact. Washington needs Pakistani support, even if not as whole hearted as it would like, to be able to begin withdrawing troops from Afghanistan this summer, while Islamabad relies heavily on U.S civilian and military aid.
Adm. Mike Mullen, the chairman of the U.S. joint chiefs of staff, said Wednesday he would bring up the issue of Pakistan's ties to the militant Haqqani network when he saw Pakistani army chief Gen. Ashfaq Parvez Kayani later the same day in Islamabad.
The Haqqani network is a largely independent Afghan Taliban faction with bases in Pakistan's North Waziristan tribal region just across the border from Afghanistan. It is considered one of the most lethal forces battling U.S. and NATO troops in Afghanistan.
Pakistan's military-run Inter-Services Intelligence spy agency has links to the network's leaders that date back to the 1980s Soviet occupation of Afghanistan, when the group was also supported by Washington. But after the Sept. 11, 2001, attacks, Pakistan has insisted it has cut those ties.
Still, many analysts and U.S. officials suspect Islamabad may be trying to maintain its links to the Haqqanis so that it can use them as a means of retaining influence in Afghanistan -- and keeping a bulwark against archrival India -- after the Americans leave.
"The ISI has a long-standing relationship with the Haqqani network, that doesn't mean everybody in the ISI but it's there ... I believe over time that has got to change," Mullen said in the GEO TV interview.
In a statement issued after meeting with Mullen, Kayani did not mention the Haqqanis, and said both sides were determined to keep their relationship intact.
The statement said Kayani told Mullen that he "strongly rejects negative propaganda (about) Pakistan not doing enough".
He also said the army's multiple offensives against insurgent groups in the northwest are evidence of Pakistan's "national resolve to defeat terrorism."
Kayani also slammed the ongoing U.S. missile strikes in Pakistan. Those strikes often hit North Waziristan, where the Haqqanis are based and the one tribal region along the Afghan border where the army has not staged an offensive despite U.S. pleas.
Pakistan has long denounced the drone-fired missile strikes as violations of its sovereignty, but it is widely believed to secretly cooperate with at least some of the attacks. But in mid-March, Kayani issued a rare statement denouncing one such attack after it killed nearly 40 people. A U.S. official said the target was justified, but Kayani said dozens of innocent tribesmen died.
That strike came the day after the American CIA contractor Raymond Davis was released after compensation was paid to the families of the victims. The Davis case badly strained relations, with Pakistan refusing to take a stand on whether Davis had diplomatic immunity from prosecution as the U.S. embassy claimed.
The bombing late Thursday tore through a club in a violent corner of Karachi when scores of people were playing cards and other gambling games, said police officer Irshad Sehar. He said it was not immediately clear whether the bomb was planted or thrown.
Provincial health minister Sagheer Ahmed said 15 people were killed and 35 injured.
Ahmed said the perpetrators were likely "criminal or mafia elements" not militants.
Karachi, a lawless city of around 16 million, often sees violent attacks by criminal and political gangs over the control of illegal businesses and protection rackets. Islamist militants have also carried several attacks there in recent years.