Tokyo, March 20 (IANS) Japan continued efforts to avert a nuclear meltdown Sunday, shooting tonnes of water into two reactors in the stricken Fukushima nuclear plant and succeeded in restoring power in another reactor as the toll in the quake-tsunami mounted to 7,700, officials said.

Workers succeeded in putting water into the No.4 reactor in Fukushima, in northeastern Japan. The defence ministry said about 80 tonnes of water was shot into the reactor's spent fuel pool during a 70-minute operation that ended at 9.30 a.m. (0030 GMT).

Meanwhile, the Tokyo fire department shot over 2,000 tonnes of water into the No.3 reactor's spent fuel pool in an overnight mission that lasted for over 13 hours till 3.40 a.m. Sunday, Xinhua reported.

The cooling system has been reactivated at the No.6 reactor, thanks to restoration of electricity supply. Its temperature has dropped to around 40 degrees Celsius, according to the plant operator, Tokyo Electric Power Co.

The company said workers were trying to restore electricity at the No.1 and No.2 reactors in an effort to restart the cooling system.

The power plant, about 220 km northeast of Tokyo, was stricken by a devastating earthquake and tsunami March 11, triggering a series of explosions and fire at four of its six reactors.

The National Police Agency Sunday said 7,700 people were confirmed dead, while 11,651 were still unaccounted for across the country.

Kyodo News agency reported that some 120,000 personnel from the military, police and firefighters were involved in rescue and relief efforts.

Officials said international aid that arrived in Japan included 230,000 water bottles from South Korea, 500 generators from Taiwan and 25,000 blankets from Canada.