''We have received information that some suicide attackers have reached Islamabad, after which all intelligence agencies have been directed to be vigilant to foil their designs,'' interior ministry spokesman Javed Iqbal Cheema said.
Dawn newspaper quoted Cheema as saying that security agencies were holding separate meetings to prepare plans to net the bombers.
The number of security personnel deployed in and around the Diplomatic Enclave has been increased.
The interior ministry spokesman said at a weekly briefing that written orders had been sent to intelligence agencies to take necessary steps to foil any terror plan.
He did not say who the suicide bombers were and which group and area they belonged to.
The spokesman said security of foreign nationals, especially Chinese, had been increased by the ministry's Foreigners Security Cell.
Mr Cheema said that the government was taking several steps to curb militancy in tribal areas aading that '' it has been realised that the wave of terrorism cannot be suppressed by force and we have to change the mindset of the militants to tackle the problem''.