Indian villagers claim they are being attacked by flying spheres which emit red and blue lights. At least seven people have died in the last week of unexplained injuries in the state of Uttar Pradesh.

Many others have suffered scratches and surface wounds which they say happened while they slept.

Raghuraj Pal, whose neighbour Ramji Pal died recently in Shanwa, said: "A mysterious flying object attacked him in the night. His stomach was ripped open. He died two days later."

Doctors say such stories are nothing but mass hysteria while police say insects might be responsible.

"More often than not the victims have unconsciously inflicted the symptoms themselves," said Narrotam Lal, a doctor at King George's Medical College in Lucknow.

"It is a nine centimetre long winged insect that leaves rashes and superficial wounds," Supt Kavindra Singh told the Press Trust of India.

But villagers are unconvinced. In the worst-hit Mirzapur district, people have stopped sleeping outdoors despite the sweltering heat and frequent power outages.

Villagers have formed protection squads that patrol Shanwa, beating drums and shouting slogans such as, "Everyone alert. Attackers beware."

"I can't sleep because of pain," said Kalawati, 53, who says she was attacked last week. "It was like a big soccer ball with sparkling lights."