The review was carried out after Central security agencies received an alarming intelligence input that militants had carried out a reccee to plan a suicide attack on Mukherjee, who was earlier the Defence Minister.

Intelligence sources said certain Pakistani and Bangladeshi based militant outfits like Lashkar-e-Toiba and Jaish-e- Mohammad were named as groups, which were planning to carry out the attack on Mukherjee, who already has high Z-Plus category security cover.

The Home Ministry has also directed Delhi and West Bengal police forces to take adequate measures and ensure fool-proof security for the Union Minister, the sources said.

Besides holding the key portfolio of External Affairs, Mukherjee also heads the UPA-Left committee on Indo-US civil nuclear deal and various Group of Ministers (GoM) constituted on important issues.