Islamabad, May 26 : As Pakistan Tehreek-e-Insaf (PTI) Chairman Imran Khan's caravan is on its way to famous D-Chowk after entering Islamabad on Thursday, the federal government has called in the Army for the security of the capital's Red Zone. "Pursuant to the law and order situation in the Islamabad Capital Territory, the federal government, in exercise of powers conferred under Article 245 of the Constitution of Islamic Republic of Pakistan, is pleased to authorise deployment of sufficient strength of troops of Pakistan in Red Zone in ICP in aid of civil power," The Express Tribune reported citing a statement issued by the Interior Ministry as saying. The statement said that the decision was taken for the protection of important government buildings including the Supreme Court, Parliament House, Presidency, Prime Minister's Office and others. It further said that the exact number of troops to be deployed will be worked out by the Pakistan Army authorities in consultation with the ICT administration, The Express Tribune reported. Earlier in the day, the former Prime Minister had asked his supporters to reach the D-Chowk of federal capital. "The workers present at D-Chowk wait for me... I am bringing a sea of people there," he announced atop his container. However, soon after the announcement, the Capital Police vowed to stop anyone from entering the Red Zone. "If anyone tried to come near the Red Zone, he will be dealt with an iron hand," Islamabad IG Akber Nasir said. Nasir said that he has asked the officers not to use force in other areas of the capital. He also appealed to the protesters not to damage public property and remain peaceful. /IANS