GUWAHATI, India -- Disease and hunger stalked nearly 700,000 people trapped by raging floods in India's northeastern state of Assam as food supplies began to dry up and roads were cut off after heavy rains, officials said Saturday.

Assam Flood Control Minister Nurzamal Sarkar told AFP the flood situation "worsened" overnight with two more districts reeling under floodwaters with the river brahmaputra and its tributaries flowing above the danger level.

A week of monsoon rains has submerged 17,500 villages, marooning up to 700,000 people in Assam.

The Dhemaji district 465 kilometers (288 miles) east of Assam's capital Guwahati has been the worst hit, with flash floods inundating at least 15,000 villages and leaving up to 550,000 people stranded.

Villagers were taking shelter in makeshift camps and in schools, with their homes either washed away or inundated by floodwaters, officials said.

In six other districts, at least 150,000 people have been hit in about 2,500 villages.

"Road communication between Dhemaji district and the rest of Assam has remained snapped for the past five days with floodwaters overtopping the national highway in at least three places," said Biswaranjan Samal, Dhemaji district magistrate.

Samal said supplies of essential goods have stopped, leading to a "crisis-like" situation in the district.

"Very soon, the existing stocks would dry up and we might have to face scarcity of food unless road links are restored," Samal said.

The district magistrate said that unless makeshift bridges were constructed along the route to Dhemaji, essential supplies could not be sent.

However, there have been no reports of casualties.

"There are virtually no communication links and even if some people have died or drowned we would get those reports after a few days," a police official in Dhemaji said by telephone.

The Assam Health Ministry has sounded an alert fearing an outbreak of disease in flood-hit areas.

"We are particularly worried about the possibility of water-borne diseases breaking out and hence taking the matter very seriously," Assams Junior Health Minister Rupam Singh Rongkong told AFP. "We have asked doctors and health workers to provide medical help to the villagers immediately to avoid an epidemic."

With more heavy rains forecast and flood control officials warning that the Brahmaputra River was rising steadily, the Assam government has put the army on standby to assist the police, paramilitary units, disaster management teams and the civil authorities.

"There have been breaches of embankments at various places in morigaon district and Dhemaji and many more dykes are being threatened by the gushing floodwaters," the flood control minister said.

"There has been a steady movement of animals from the park to safer areas with the floodwaters already submerging the lowlands inside the sanctuary," Vasu said by telephone.