NASSAU, Bahamas — Tropical Storm Cristobal grew in strength Sunday and lashed parts of the Bahamas and the Turks and Caicos Islands with heavy rainfall and white-crested surf.
The storm was upgraded from a tropical depression Sunday morning. The U.S. National Hurricane Center in Miami said the storm may strengthen into a hurricane on Wednesday while over the open waters of the Atlantic. The storm's center was expected to curve away from the U.S. East Coast.
Residents in the sparsely populated southeastern Bahamas and the tiny British Caribbean dependency of the Turks and Caicos Islands hunkered down as Cristobal's rains pelted windowpanes.
Authorities in the Bahamas, a sprawling archipelago off Florida's east coast that is accustomed to stormy weather, urged people on southeastern and central islands to complete "all the necessary preparation to protect life and property, primarily from flooding in flood-prone areas."
Capt. Stephen Russell, head of the islands' emergency management agency, said there had been no reports of damage by late Sunday morning. Air traffic to the southeastern Bahamian islands had not been suspended, but sea vessels were advised to remain in port, he said.
Officials in the Turks and Caicos Islands advised residents on Sunday to remain indoors and "leave home only if absolutely necessary."
Cristobal originally formed as a tropical depression over the Turks and Caicos Islands on Saturday. It was the fourth depression of the Atlantic hurricane season.
By late Sunday morning, the tropical storm had sustained winds of about 45 mph (75 kph) and was located about 130 miles (205 kilometers) east of the Bahamas' Long Island.
The slow-moving storm was tracking north-northwest at about 7 mph (11 kph). U.S. forecasters said there should be a decrease in forward speed over the next couple of days, meaning Cristobal's center is expected to move near or over the central Bahamas through Monday.
A tropical storm warning was in effect for the Turks and Caicos Islands and for the southeast and central Bahamas, with forecasters saying it could bring up to 8 inches (20 centimeters) of rain to the islands through Tuesday.
Before strengthening into a storm, it had downed several trees and power lines on the U.S. Caribbean island of Puerto Rico as a low-pressure system, leaving more than 17,000 people without power and nearly 5,600 without water.
Police said in a statement that a small bridge collapsed Saturday in the central town of Barranquitas, isolating some 25 families in the area. No one was injured.
AP writer David McFadden contributed to this story from Kingston, Jamaica.