Gunmen have kidnapped a U.S. citizen from his house in Pakistan's eastern city Lahore, officials said.
The U.S. Embassy identified the man as Warren Weinstein, who works for the development contractor J.E. Austin Associates.
Police said eight to 10 kidnappers broke into the man's house in an upscale neighborhood around 3:30 a.m. on August 13 and forced his driver to knock on his door before abducting him.
An unidentified senior police official told reporters in Islamabad police had little more information.
"So far we have just investigated the location and the events that happened, we have collected the evidence," the official said.
J.E. Austin Associates works with the U.S. government's aid arm. Weinstein is reported to have been working on a development project in the country's lawless tribal areas.
Security guards on duty were reported to be preparing for fasting as required by the Islamic month of Ramadan.
No one has claimed responsibility for the abduction, and police said the motive for the attack was not immediately clear.
Militant groups have often targeted foreigners in the past. Criminal gangs also carry out frequent kidnappings of Pakistanis for ransom.
The U.S. State Department issued a travel warning for U.S. citizens this week.
Ties between the United States and Pakistan have been seriously strained since U.S. forces killed Osama bin Laden in Pakistan earlier this year.
compiled from agency reports