New Delhi, Sep 8 - Anonymous calls warning of bomb blasts Tuesday affected two busy Delhi Metro stations, two hospitals and three government buildings, causing panic and leading to the evacuation of thousands from some of these places. In the end, it all turned out to be one big hoax.

A Delhi Police spokesman said that their control room got four telephone calls between 10 a.m. and 2.21 p.m., the first one warning that bombs would go off soon at the Ram Manohar Lohia Hospital in the heart of the capital, the Palika Kendra as well as Vikas Minar.

The caller called back again to say that the bomb had been placed at the Safdarjung Hospital in south Delhi and not at the Lohia hospital. However, a search was ordered in both hospitals.

Two more phone calls in the afternoon said bombs would also explode at the Rajiv Chowk and Chandni Chowk Metro stations, two of the busiest in the network. Another call warned of mayhem at the Town Hall in Old Delhi, housing the Municipal Corporation of Delhi and the office of the mayor.

'Police were immediately pressed into service at these places. Bomb experts and dog squads were also sent. Ambulances and fire engines were brought in,' a police officer said.

The Safdarjung Hospital, one of the oldest in the capital, was evacuated, affecting hundreds of people, many of them sick.

'I was in the OPD at around 10.30 a.m. when we were asked to immediately leave the hospital building,' said Rakesh Kumar, a patient who had come to the hospital.