The flood-swollen Jamna and Ganges rivers rampaged through northern India yesterday, with government officials predicting that the situation would get worse.

Nearly 1,000 persons have already been killed by the floods, caused by the heaviest monsoon rains in memory across northern India.

An official spokesman said yesterday that since the annual monsoon rains started in June, flood waters have swamped more than 46,000 villages and destroyed or damaged 600,000 houses.

Defense Minister Jagjivan Ram ordered India's army, navy and air force into action yesterday to help in rescue and relief operations.

In New Delhi, where the Jumna River displaced 350,000 residents, hundreds of children were separated from their parents. The government said one group of 37 children marooned on the roof of their school went hungry for three days.

Army troops have been ordered to reinforce two man-made embankment that protect the north-central city of Allahabad where the Ganges and Jumna rivers meet 375 miles southeast of New Delhi. The Ganges, considered Hindu India's sacred river, was reported at nearly six feet above the danger level.

Minister Ram said the situation in Allahabad would remain critical for two days. The city of 500,000 is in Uttar Pradesh, India's most populous state, which contains two-thirds of the flooded villages.

In Agra, low-lying areas were evacuated and travel agents were told to cancel tourist trips to the Taj Mahal, a Mogul tomb regarded as one of the wonders of the world.

The beautiful white marble-doomed monument stands on the bank of the Jumna River but is out of reach of the floods. However the surrounding gardens were likely to be inundated and one Agra official said the river could exceed the record 1924 flood level.

Many northern suburbs of New Delhi, the Indian capital, remain under water. Although record-high waters of the Jumna have receded slightly, officials say the river still threatens residential areas.

The government said it has allocated $60 million for relief work.

Foreign voluntary agencies, including CARE, have begun aiding flood refugees. CARE received a $25,000 donation yesterday from U.S. Ambassador Robert Goheen's government-supplied discretionary fund for use in its relief activities here.

CARE is supplying 625 tons of soyfortified bulgar wheat to stranded villagers in Uttar Pradesh and West Bengal, on the Bay of Bengal, said Alan Trumbell, director for India. It is also supplying 50,000 pieces of clothing and 200,000 plastic tarpaulins for emergency shelter.

Ram appealed to the rest of India for aid, saying if each Indian household would donate the equivalent of a meal, much suffering would be eased. He said the government could not cope with such a large disaster.