The toll in Sunday's devastating tsunami has risen to 4,500 in Tamil Nadu and Pondicherry, official sources said.

Unconfirmed reports, however, put the toll at over 5,500.

In Nagapattinam alone, more than 2,500 people have died. Over 500 bodies have been recovered from Velankanni.

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Water levels have receded in many places in low-lying areas of coastal Tamil Nadu and Pondicherry, helping relief workers to speed up operations.

At Nagapattinam, volunteers are helping the local administration in relief work. Army and Indian Air Force helicopters are also assisting local officials.

Mass burials are taking place in many of the affected areas.

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Kanyakumari, another badly hit district in the state, has reported 625 deaths, followed by Cuddalore with 425.

In Chennai city about 200 lives have been lost. At Kalpakkam, nearly 80 people have perished, sources said, adding that at least five employees of the Indira Gandhi Centre for Atomic Research were among the dead.

In Pondicherry, which has reported nearly 400 deaths, including 280 in Karaikal, more than 30,000 people have been rendered homeless.

Civic authorities in Chennai have opened six medical camps to treat the injured. Those rendered homeless have been accommodated in marriage halls and schools.

Also see: Tsunami: Waves of destruction