North Korea has fired another ballistic missile, the latest in a series of launches that have raised tensions with its neighbours and the US.

The Pentagon said it believed it was an intercontinental ballistic missile that flew for about 1,000km (620 miles) and fell into the Sea of Japan.

South Korean news agency Yonhap said that the missile was launched from Pyongsong, South Pyongan province.

North Korea's last ballistic missile test was in September.

That came days after it had conducted its sixth - and largest - nuclear test.

The US said the latest launch happened at about 03:30 local time (18:30 GMT).