Antigua and Barbuda has recorded its 20th earthquake in less than a week, as a series of tremors continues to rattle the eastern Caribbean.

The latest quake, measuring magnitude 4.0, struck at 2:13am local time about 264 kilometres east-southeast of St John’s, according to the University of the West Indies Seismic Research Centre (SRC). It occurred at a depth of 10 kilometres.

The swarm began on Monday, 27 October, with a powerful magnitude 6.7 earthquake, followed by several strong aftershocks including magnitudes 6.1 and 5.4. Most of the tremors have been centred offshore between Antigua and Barbuda, Guadeloupe and Dominica.

The SRC said it is closely monitoring the activity, noting that the preliminary data for the latest quake may be revised.

The eastern Caribbean lies on the boundary between the North American and Caribbean tectonic plates — one of the most active seismic zones in the region. Residents have been urged to stay alert and follow advice from local disaster officials.