Image copyright Reuters Image caption Heavy rain hit southern Japan as people voted on Sunday

Japanese Prime Minister Shinzo Abe's coalition has won a resounding victory in Sunday's general election, according to exit polls.

On hearing of his victory he said he would "firmly deal with" threats from North Korea.

The public broadcaster NHK put Mr Abe's Liberal Democratic Party-led (LDP) coalition at 312 seats, allowing it to retain its two-thirds "super majority".

This is vital to his ambition to revise Japan's post-war pacifist constitution.

Mr Abe has pushed for a shift in Japan's defence policy, calling for formal recognition of the military in the constitution.

He said he would try to "gain support from as many people as possible" for the task.

He said on Sunday: "As I promised in the election, my imminent task is to firmly deal with North Korea.

"For that, strong diplomacy is required."

Mr Abe announced the election on 25 September, saying he needed a fresh mandate in order to deal with the "national crises" facing Japan.

The crises include North Korea, which has threatened to "sink" Japan into the sea. Pyongyang has also fired two missiles over Hokkaido, the northernmost island in Japan.

A win in the election raises Mr Abe's chances of securing a third three-year-term as leader of the LDP when the party votes next September.

That would give him the opportunity to become Japan's longest serving prime minister, having been elected in 2012.

Japan went to the polls on Sunday as Typhoon Lan lashed parts of the country. The category four storm brought strong winds and heavy rain to the south of the country, causing flights to be cancelled and rail services to be disrupted.

It is expected to blow into the Tokyo area early on Monday, the Japan Meteorological Agency said.

Speaking to the BBC, one observer described voting for Mr Abe's Liberal Democratic Party as TINA, or "there is no alternative".