HYDERABAD, India - Mosquito-borne encephalitis has killed five more children in a southern Indian state, raising the death toll to 140, officials said Monday.

At least 257 other children have been affected across Andhra Pradesh state over the past eight weeks, Health Minister K. Sivaprasada Rao said in the state capital, Hyderabad.

Five more deaths were reported Sunday, state health official Dr. P Laxmi Raqjyam said.

But Rao said the situation was now under control and the number of cases was declining.

The children have been killed in a rare summertime outbreak of viral meningo-encephalitis, health officials said. Most of the victims were poor, malnourished children from rural areas who may have succumbed because of a sudden change in weather from intense summer heat to monsoon rains.

Many children might have died because they could not be taken to health centers in time, experts said.

Officials are worried that the disease may spread during an upcoming religious gathering for the Godavari Pushkaram festival. Millions of people are expected to assemble along rivers in the state considered holy by Hindus.

During the July 30-Aug. 10 pilgrimage, observed once each 12 years, devotees will take baths in seven districts of the state.

Rao said the government was taking steps so that diseases like encephalitis do not spread during the festival.

Health officials say two federal laboratories in New Delhi and the western city of Pune have tested the virus and found no link to the West Nile virus that has caused encephalitis in the United States.

The disease hits India every year, but usually in the drier months of October to December, and it usually causes fewer deaths. According to the World Health Organization, encephalitis is endemic to Asia; around 50,000 cases are recorded every year.

India, a poor nation of more than a billion people, has scant health care in rural areas. Most children in villages are first treated with home remedies.

The last big encephalitis outbreak in Andhra Pradesh was in 1999, when 965 cases were reported, with 200 deaths. Throughout Asia last year there were 50,000 cases and 10,000 deaths.

No treatment is available for meningo-encephalitis, but doctors can treat the symptoms. There are vaccines, and the usual action is to vaccinate a population once there has been an outbreak.