Two US helicopters landed in Kala Dhaka area of Swat before the operation in Abbottabad, in which Osama bin Laden was killed on May 2, reported a private TV channel on Thursday. The ground distance from Kala Dhaka to Abbottabad is 150 kilometres, having mountainous terrain. An witness said that the helicopters remained in Kala Dhaka for 30 minutes. There are clear marks left by helicopters in the fields. The intelligence agencies have collected the evidence from the site, that according to an eye witness, also included an iron rod which the owner of the field had discovered. The agencies also picked up gasoline soaked soil from the site. However, the government of Khyber-Pakhtoonkhwa province has expressed a total lack of knowledge of any such incident. Provincial Information Minister Mian Iftikhar said the police of district administration had informed nothing in this regard.