The U.S. Embassy in Islamabad demanded that Pakistan stop detaining American diplomats at police checkpoints on the country's roads -- an unusual public complaint intended, in part, to counter rumors of U.S. plots against Pakistan. U.S. officials privately say the traffic stops, which they describe as harassment, are part of a broader campaign aimed at limiting America's diplomatic presence in Pakistan. The officials say they believe the campaign is being driven by elements in the military and the Inter-Services Intelligence spy agency. Pakistan is a U.S. ally, but many of its officials, soldiers and spies are mistrustful of Washington's intentions in neighboring Afghanistan and growing ties to archrival India. Many ordinary Pakistanis, meanwhile, believe the U.S. is pouring spies into Pakistan and aims to take away its cherished nuclear arsenal. U.S. diplomats also say that scores of American diplomats and officials were waiting on visas to come to Pakistan or extensions to remain in the country. U.S. officials say the delays risk undermining joint efforts to beat back the Taliban and al Qaeda and stabilize Pakistan. Many of the people waiting on visas are to help oversee a $7.5 billion civilian aid package. The harassment and visa delays were partly an attempt to keep the U.S. from nearly doubling the size of its embassy in Pakistan, a U.S. diplomat claims. "They're really suspicious of what we're doing here," the diplomat said. The embassy's statement called for "immediate action" by Pakistan "to cease these contrived incidents involving U.S. mission vehicles and personnel." It cited an incident Wednesday when a U.S. vehicle with two Pakistani employees of the U.S. mission and a police constable guarding them were briefly detained in Gwadar, in southern Pakistan. The embassy said the car was properly registered as a diplomatic vehicle. U.S. officials say they first thought such traffic stops were the work of overzealous police officers following a series of Taliban attacks. But the stops have persisted, despite complaints to the government. "It's become increasingly evident that these are more than just routine security checks," said another U.S. diplomat. In one case in Lahore, an American official was detained for six hours; in another, a vehicle was confiscated for a few days, said the diplomat. In some instances, television crews were waiting at the checkpoints, indicating a degree of premeditation. A spokesman for Pakistan's foreign ministry, Abdul Basit, denied U.S. diplomats and officials were being harassed and said visas were being delayed because the applicants hadn't furnished needed information. "The vehicles are detained only when they do not have proper registration papers," he said. "It only shows that our security officials are vigilant and they should be appreciated for it." In several cases, he said, vehicles carrying U.S. officials used fake license plates; in others, another official said, the vehicles carried unregistered firearms and the passengers couldn't prove their identity. The U.S. has denied this. Such allegations have become a feature of stories about American conspiracies against Pakistan that now dominate a section of the Pakistani media. The stories have persisted, despite strenuous U.S. denials -- a significant motivation behind the embassy's public complaint Thursday, diplomats said. "We felt like we had to address it a little more openly," said one of the U.S. diplomats. "We're trying to address certain quarters of the Pakistani public that thinks there is something nefarious going on here when that's just not the case." The diplomat said all U.S. vehicles carry proper diplomatic documentation but don't bear diplomatic plates because that would make them an easy target. (wsj)