A powerful 6.4 magnitude earthquake struck in the Atlantic Ocean Wednesday, north of Brazil and east of French Guiana, the US Geological Survey said.
The quake hit at 1308 GMT about 1260 kilometers (780 miles) north-northeast of Parnaiba, in the Brazilian state of Piaui, and 1542 kilometers (958 miles) east-northeast of Cayenne, the capital of France's South American overseas territory French Guiana.
The quake's epicenter was at a depth of 10 kilometers (6.2 miles) in the Central Mid-Atlantic Ridge, the USGS said.
The Hawaii-based tsunami warning center said that the quake did not pose a widespread tsunami risk for the Caribbean.
"However there is the small possibility of a local or regional tsunami that could affect coasts located usually no more than a few hundred kilometers from the earthquake epicenter. Authorities in the region near the epicenter should be made aware of this possibility," it warned in a statement.