Senior Bharatiya Janata Party leader Venkaiah Naidu on Tuesday said the Centre has informed senior leader Lal Kishenchand Advani and party President Rajnath Singh that the threat to their lives will be high while they are on the move during the Bharat Suraksha Yatra beginning on April 6.

"Yes, we have received intimation from the government about this. They have told us to take great care as the two leaders pass through various states. We have been told that the two leaders should wear bullet-proof jackets and travel in bullet-proof vehicles," Venkaiah Naidu said in New Delhi.

Official sources said the major concern is Pakistan's Inter Services Intelligence-trained terrorists, who are now operating in India through Bangladesh.

The other concern is about the Naxals, who have are active in Andhra Pradesh, Jharkhand, Madhya Pradesh and Bihar.

"We will make certain that the yatras pass off peacefully without an incident. But, if the situation demands, we would have to call of the yatras," said a senior government official.

While Advani will begin his yatra from Rajkot, Rajnath Singh will embark upon his yatra from Puri in Orissa.

Security agencies are working overtime to evolve strategies to protect the two leaders.

Intelligence agencies will continue to provide inputs to the BJP central leadership, who, in turn, will pass it on to the local coordinators.

Advani will cover around 6,000 kilometres and will pass through Maharashtra, Karnataka, Andhra Pradesh, Orissa, Madhya Pradesh, Rajasthan, Uttar Pradesh and Haryana and Delhi.

Rajnath will pass through Orissa, West Bengal, Jharkhand, Bihar, Uttar Pradesh, Himachal Pradesh, Jammu and Kashmir [Images], Punjab, Haryana, Rajasthan and Delhi.