Tokyo: It is just a miracle that Japanese police on Sunday found an 80-year-old woman and a 16-year-old boy alive under piles of rubble nine days after a massive earthquake and tsunami  rocked northeastern Japan, while the number of deaths and those missing from the disaster surpassed 20,000.

The two - Sumi Abe and her grandchild Jin Abe - answered police calls in Ishinomaki, Miyagi region, one of the worst-hit areas, and public broadcaster NHK showed footage of helicopter ferrying them to a local hospital.

The two were eating a meal when the 9-magnitude earthquake struck the area. They managed to survive, eating some food in the refrigerator. Sumi got mildly dehydrated while Jin suffered from hypothermia.

Meanwhile, the number of dead and missing rose to 20,405 as of Sunday noon - 8,133 deaths and 12,272 those who are still unaccounted for, Kyodo News reported citing the National Police Agency.

A total number of deaths is expected to be much higher as more than 15,000 people perished in Miyagi Prefecture alone, local police chief said.

More than 360,000 evacuees have to spend another night at shelters in 14 prefectures, Kyodo said, while more relief supplies arrived from home and abroad.

Such supplies included 230,000 water bottles from South Korea, 500 generators from Taiwan and 25,000 blankets from Canada.

Some 120,000 personnel from the Self-Defence Forces, police and fire fighters were involved in rescue and relief efforts.