WASHINGTON — A 5.9 magnitude earthquake rocked Puerto Rico on Saturday, the latest in a series of powerful tremors that have shaken the US territory in recent days, the US Geological Survey reported.

The latest quake occurred at 8:54 am local time (1254 GMT) around 13 kilometers (eight miles) southeast of Guanica, a town on the island's southern Caribbean coastline that was hard hit by earlier quakes.

The USGS revised its initial report of a 6.0 magnitude quake to 5.9.

It follows a 6.4 magnitude quake on Tuesday that killed one person, knocked out electric power and caused widespread damage.

Puerto Rico Governor Wanda Vazquez declared a state of emergency after Tuesday's quake, which forced an automatic shutdown of the power grid.

Puerto Rico's electric power authority reported outages in the towns of Ponce, Lares, Adjuntas and San German after the latest quake.

The Pacific Tsunami Information Center in Hawaii issued a statement saying there was "no significant tsunami threat" but a small possibility of tsunami waves along coasts nearest the epicenter.

The island is still recovering from Hurricane Maria, which came ashore more than two years ago as a devastating Category 4 storm.

Starting Dec. 28, a wave of tremors have swept the island, putting residents on edge.

The 6.4 quake on Jan. 7 came a day after a 5.8 magnitude quake; it was followed by major aftershocks.

Saturday's quakes were also preceded by a string of smaller tremors. — AFP