Forest and revenue department officials had conducted searches in Kurnool district, Chidambaram said, adding: 'We are keeping our fingers crossed. The police and paramilitary forces are moving towards that point... Perhaps they would be able to do a search for a couple of hours at least, then we will have to wait first light tomorrow.'

Even as rescuers combed the forest range, officials reluctantly admitted that the missing helicopter had not renewed its airworthiness certificate for two years. Experts denounced the shocking revelation.

President Pratibha Patil, now in Moscow, Prime Minister Manmohan Singh and Congress president Sonia Gandhi expressed concern over YSR's fate.

His disappearance has caused concern in the Congress, where YSR is highly regarded both for his administrative acumen and political skills. He is also credited with crushing the Maoist movement in Andhra Pradesh, a long-time ultra-Left bastion.

In a sign of desperation, chief secretary Ramakant Reddy urged anyone who got to know anything to contact the police.

'So far we have not been able to get any confirmation (about the chief minister). It is possible that because of the strong winds and heavy rains, it (the helicopter) may have landed in some unfamiliar area,' Ramakant Reddy said, adding: 'If you land in an unfamiliar forested area, getting out will be very difficult.'

He urged people living in the forested region to 'kindly help us. If you get any signal, any reliable information, contact the nearest police station'.

With no word on YSR's whereabouts, thousands of emotive supporters gathered at the Congress office in Hyderabad. Scores prayed for his safety in temples, mosques and churches in the state.

At the state secretariat, the crowds shouted: 'Long live YSR' and termed him a friend of the poor. Security personnel had a tough time controlling the crowds.

A doctor by training, YSR is one of the most influential leaders in the Congress after again leading the party to a spectacular win in the Lok Sabha and assembly elections in April-May this year.

Elected to the state assembly for the fifth time, YSR is also a four-time Lok Sabha MP and holds the record of never losing an election. He is the first Congress chief minister to rule Andhra Pradesh for five years and then retain office.