PESHAWAR: An American detained for visa violations in northwest Pakistan is a contractor who had worked on a US-funded construction project in the region, a security official said.

Pakistan's intelligence agency says it is scrutinizing the details of Americans in the country after the arrest last month of a CIA employee for shooting dead two Pakistanis in the eastern city of Lahore, but it was unclear whether the arrest of Aaron Mark DeHaven in Peshawar on Friday was directly related.

The killings in Lahore have sharply raised tensions between Pakistan's spy agency and the CIA and have also unleashed a new round of anti-American rhetoric in the country.

On Saturday, more than 300 members from the Jamaat-ud-Dawa charity, which has militant links, rallied in Lahore, urging the government to hang the detained CIA contractor, Raymond Allen Davis.

"Expel all the CIA agents," said Amir Hamza, a leader of the charity.

The rally came hours after DeHaven appeared in court in Peshawar, and a judge ordered he remain in custody for 14 more days while police investigate him.

The security official said DeHaven was a contractor who had worked on at least one construction contract for the US government in the region, declining to give more details.

He said DeHaven is a 34-year-old from Virginia who is married to a Pakistani woman. The official asked that his name not be published because of the sensitivity of the case.

DeHaven's application form for a work visa says he works for Catalyst Services.

The company's website says it performs logistics, "life support" and construction services around the world and lists contact numbers in Pakistan, Dubai and Afghanistan.

It says its management teams have US Army or Defense Department backgrounds.

The United States makes extensive use of contractors to implement its billion-dollar aid and military projects in Afghanistan and Pakistan.

The US Embassy said it had seen media reports about the arrest and was trying to arrange consular access to DeHaven.'