SEOUL: A strong 6.7-magnitude earthquake struck at sea off the border between North Korea, China and Russia on Thursday but there were no reports of damage and no tsunami warning was issued, seismologists said.
The quake hit at 10:13 am (0113 GMT), 111 kilometres (69 miles) northeast of the North Korean city of Chongjin at a depth of 562 kilometres, the US Geological Survey said.
The Hawaii-based US Pacific Tsunami Warning Centre said the quake, around the same distance from Vladivostok in Russia and Yanji in China's Jilin province, did not generate a destructive tsunami.
The Korea Meteorological Administration in Seoul confirmed the quake but said it had no impact on South Korea. The office said it relied on US data for details.
An official at the seismological bureau in Changchun, the capital of Jilin province on the border with North Korea, said the quake had not been felt there due to its depth.
While destructive quakes in the region are rare, other parts of China are frequently badly-hit.
An 8.0-magnitude quake rocked southwest China's Sichuan province in May last year, leaving more than 68,500 people dead.