Pune/Ahmedabad, Aug 9 - A 42-year-old school teacher from a village near Pune and a 43-year-old non-resident Indian (NRI) man who had flown from the US to Ahmedabad died of swine flu Sunday, taking the death toll from the raging virus in India to four.

Authorities in Maharashtra and Gujarat -- which account for all four deaths -- were on high alert after the latest fatalities as Delhi's Chief Minister Sheila Dikshit called an emergency meeting in the capital.

Teacher Sanjay Kokare died in Pune's Sassoon Hospital at around 1 a.m. He is the third swine flu victim in Maharashtra, Pradeep Awate, head of Maharashtra's Swine Flu Control Room, told IANS.

Kokare had been admitted initially to a hospital in Khedegaon village near Pune July 31, said Ashok Ladda, additional director of the family welfare department.

'He improved and was at home for two days. But his condition deteriorated and he was taken to a private hospital in Pune. He was shifted to Sassoon Hospital two days back and was on ventilator. He did not revive,' Ladda said.

Pravin Patel, a resident of Atlanta in the US, died of Influenza A (H1NI) at the civil hospital in Gujarat's main city Ahmedabad Sunday. He and his wife had tested positive for swine flu Saturday, a week after arriving in India.

'This is the first swine flu death in Ahmedabad. The patient had other complications as well. He had viral pneumonia, which is very difficult to treat. His haemoglobin was low. All these added to the complications of swine flu,' Gujarat Health Minister Jaynarayan Vyas told IANS.

Patel was brought to the hospital with a respiratory tract infection and was under ventilation Aug 5-7. He was taken off the ventilator for a few hours Aug 8 after his condition improved. But his condition deteriorated again.

Patel's wife, whose name is not available, is in critical condition.

Reeda Shaikh, a 14-year-old student, was India's first swine flu victim.