Japanese Prime Minister Shinzo Abe has pledged to press ahead with his programme of economic reform after his Liberal Democratic Party claimed victory in elections for the country's Upper House of parliament.

Early results from state broadcaster NHK show the Liberal Democratic Party secured 64 of the 121 seats being contested, nearly doubling the number it held before the election.

Along with the 10 seats won by their coalition partners, a small Buddhist party, the result is enough to give the Liberal Democratic Party control of the 242 seat house, and puts it in charge of both houses of parliament for the first time since 2007.

The result ends the years of Japan's so-called "twisted parliament", in which different parties were in control of each house, factionalism reigned and there was a quick succession of prime ministers.

Abe hailed the result as a victory for so-called 'Abenomics', the prime minister's three pronged economic reform programme that has restored tentative growth after two decades of economic decline.

Though the Upper House is less powerful than the Lower House, which elects the prime minister, it has the power to block legislation. With the Liberal Democratic Party now in charge of both houses, Abe will be able to pass new laws with more freedom.

Their rivals, the Democratic Party, now hold 11 seats in the Upper House, significantly down on the 44 they held before the election, with many blaming the party for a bungled response to the Fukushima nuclear reactor disaster.