Washington: US Defence Secretary Robert Gates observed that Libyan leader Muammar Gaddafi’s forces were placing bodies of the people he’s killed at the site of allied air strikes so as to make an impression of civilian causalities.

"The truth of the matter is we have trouble coming up with proof of any civilian casualties that we have been responsible for," said Gates.

"We do have a lot of intelligence reporting about Gaddafi taking the bodies of the people he's killed and putting them at the sites where we've attacked," added Gates.

"We have been extremely careful in this military effort, and not just our pilots but the pilots of the other coalition air forces have really done an extraordinary job," he said.

As part of a UN Security Council mandated 'no-fly' zone over Libya, an international coalition- headed by the United States, Britain and France-has struck Gaddafi's air capabilities and sought to protect Libyan civilians.