The U.S. says there is no truth in the reports, but they have resonated with the many Pakistanis familiar with allegations that Blackwater employees were involved in unprovoked killings of Iraqi civilians.

Police official Rana Akram said that two Inter-Risk employees were arrested and being questioned. He said authorities were also seeking the company's owner, a retired Pakistani army captain.

Reporters were shown the weapons – 61 assault rifles and nine pistols – that were seized by dozens of police from the sites in pre-dawn raids in the capital, Islamabad.