New Delhi - A searing heatwave across India has claimed at least 120 lives as officials warned that deficient rainfall may result in lower agricultural output and higher food prices, officials and news reports said on Thursday.

Soaring temperatures accompanied by power outages and water shortages sparked off angry protests in the national capital New Delhi and the financial hub of Mumbai.

Fifty-eight people died in eastern Orissa, the state worst-affected by the heatwave, VN Sahu, an official at the emergency control room in state capital Bhubaneshwar said on the telephone.

In northern Uttar Pradesh state, 30 people have died of sunstroke, the Deccan Herald newspaper reported. Heat-related deaths have been reported since last month.

School vacations were extended as the heat-wave toll mounted and the monsoon rains, which usually hit eastern and northern India by the second week of June, were yet to arrive.

Temperatures of more than 40 degrees Celsius were recorded in large swathes of northern, central and eastern India over the past week.

In the national capital New Delhi, daytime temperatures were hovering at 43 degrees Celsius in recent days, with weather officials forecasting no respite.

The highest temperature recorded in Orissa was in the Sambalpur region where the mercury touched 46.2 degrees Celsius.

"Twelve people died in the Khurda district alone. Most of those affected by the heatwave are the poor, workers, rickshaw pullers or the farmers," Sahu said.

Meanwhile, 17 people have died since Monday in the eastern state of Jharkhand, which is reeling under scorching heat.

In the neighbouring Bihar state, seven people died from heatstroke. Eight people died in the coastal district of Vishakapatnam in southern Andhra Pradesh which has also been in the grip of a heatwave over the past few weeks, media outlets reported.

Villagers across India resorted to invocations, religious rites and rituals to prompt delayed monsoon rains, the IANS news agency reported.

Residents of Varanasi in Uttar Pradesh "married" two frogs to appease Indra, the god of rains.

Hindu priest Dev Raj Sharma, who solemnized the marriage, said there was a traditional belief that if frogs are married according to Vedic or Hindu customs, Indra, was pleased and rainfall take place within days.

India's Interior Ministry officials said they did not compile heat-related deaths, though hundreds die during the summer every year.

Indian officials have said the monsoon rains between June and September were likely to be below normal - at about 93 percent of the average.

The delayed rains and heatwave could affect agriculture and have Indian policymakers worried at a time when they were hoping farm output could play a key role in propping up the economy affected by the global recession. - Sapa-dpa