"Pakistan's parliament building was one target of a planned attack," he said.
Giving details of the plan in an interview with CNN, he said three men with suicide vests had been arrested over the past four weeks. He did not say when and where the suspects had been nabbed, The Dawn reported.
Malik called media reports regarding the presence of 50 suicide bombers in Islamabad "baseless" and has ordered an inquiry into the matter.
Malik ordered all provincial governments and the Islamabad Capital Territory Police to provide foolproof security to the people.
In a separate interview with BBC, the interior minister said it could be part of a policy not to confirm 100 per cent the death of Tehrik-i-Taliban Pakistani leader Baitullah Mehsud.
Malik was of the view that candidates for the new Taliban chief were 'petty characters' who were fighting against each other and Al Qaeda was taking decisions in the matter.
The Interior Minister said the government's anti-Taliban operations would continue during Ramazan. His remarks came after the Taliban in North Waziristan had announced that they would observe a ceasefire during the month.
Image: Pakistan Interior Minister Rehman Malik
Photograph: Reuters