North Korea condemned after announcing hydrogen bomb test

Authorities in North Korea say they have successfully carried out an underground hydrogen bomb test.

The claim, which has not been verified, drew international scepticism and condemnation.

The announcement came after reports of a tremor near the main nuclear test site in the country.

Nuclear experts have questioned whether the size of the blast was large enough to have been from an H-bomb.

Rupert Wingfield-Hayes reports from Seoul.