A magnitude-5.1 earthquake has struck northwestern Namibia, the country's Ministry of Industries, Mines and Energy has said.

The earthquake occurred at 5.22pm local time on Saturday, at a depth of less than 10 kilometres, with its epicentre about 400 kilometres northwest of the capital, Windhoek, in the Kamanjab area, according to a statement issued by the ministry. There was no immediate information on casualties or property damage.

The tremor is the second of similar magnitude to hit the Kamanjab area in just over two weeks, following a magnitude-4.9 tremor near the same area on 21 October.

Magnitude figures differ between agencies

The US Geological Survey lists the same event slightly lower, at magnitude 4.9, placing it 77 kilometres north-northwest of Khorixas at a depth of 8 kilometres at 15:22 UTC — the same moment as the ministry's 5.22pm local time. Such differences between agencies' first estimates are common, as each uses different measurement methods and station data.

Namibia is not known as a highly seismic country, but the Kamanjab area in the Kunene region has now recorded two noticeable tremors in less than three weeks. Authorities and monitoring agencies were expected to assess whether communities or infrastructure had been affected.

No tsunami warning applies to an inland tremor of this size, and no damage had been reported when the ministry's statement was issued.