Tokyo, Sep 8 (IANS): The toll from a 6.7-magnitude earthquake that struck Japan's Hokkaido prefecture earlier this week, has increased to 21 with 13 others still reported missing, the government announced on Saturday.

Chief Cabinet Secretary Yoshihide Suga told a press conference that a total of 40,000 people, including police, firefighters, Self-Defence Force personnel and Japan Coast Guard, are searching for the missing and helping the disaster-hit areas, reports Xinhua news agency.

After the powerful quake on Thursday, some 2.95 million homes in Hokkaido were without electricity as the whole prefecture suffered a power outage.

Suga said that while power was restored in most of the areas, some 20,000 households were still without electricity, and he urged homes and offices already with power to cut usage by about 10 per cent.

According to public broadcaster NHK, as of 6 a.m. on Saturday morning, some 30,000 households across Hokkaido were still without water supply.

About 12,000 people were still taking refuge in more than 430 emergency evacuation shelters across the prefecture, said the public broadcaster.