MIAMI - Hurricane Dora grew into a powerful Category 4 storm with winds of 220 kph on Thursday as it moved past Mexico's southern Pacific coast, toppling a lighthouse and destroying some small beachside restaurants.

The Mexican government discontinued tropical storm watches as Dora stayed well out to sea. But the waves generated by the hurricane battered the foundations of a small lighthouse about 35 miles (60 kilometres) east of the resort of Acapulco, toppling it Wednesday.

About 60 thatch-roofed restaurants on beaches in the area, around La Penitas and La Bocana, were damaged or swept away by the storm.

The U.S. National Hurricane Center in Miami said the centre of the hurricane was located about 265 miles (425 kilometres) south of Cabo Corrientes, Mexico, and about 500 miles south-southeast of the Los Cabos resort on the tip of the Baja California peninsula.

The fourth hurricane of the eastern Pacific season was moving northwest at about 13 mph (20 kph), and is forecast to stay offshore. It is forecast to strengthen some before weakening on Friday.

In the Atlantic, Tropical Storm Cindy formed well out to sea and posed no threat to land as it moved east. Tropical Storm Bret was forecast to weaken as it moved away from the Bahamas and well off the U.S. Atlantic coast.