Eight people died in Tropical Storm Noel that brought flooding accompanied by fierce thunderstorms to the Dominican Republic, officials reported.
At least three others people were reported missing as rains continued to lash Hispaniola, the island the country shares with Haiti, said Manuel Antonio Luna Paulino of the Dominican emergency services agency.
Noel was expected to drop as much as 20 inches (50 centimeters) of rain on Hispaniola throughout the day before heading northwest toward the Bahamas.
Luna said many people were apparently caught off guard by the ferocity of the rain.
At least five of the deaths were from drowning said Gesmin Simon, a spokeswoman for the emergency services agency.
Haitian Prime Minister Jacques Edouard Alexis said there were no immediate reports of casualties in his country, but he urged people to seek shelter and said airports would be closed throughout the day.
"It's very serious now," Alexis said at a news conference in the presidential palace. "It's moving very slowly and dropping a lot of rain."
Impoverished Haiti is prone to deadly flooding because of its steep mountains and deforested hillsides, but damage reports are often slow in reaching authorities in the capital, Port-au-Prince. Floods earlier this month killed at least 37 and sent more than 4,000 people to shelters.
Mountainous terrain weakened the storm overnight, but Noel still had sustained winds of about 45 mph (70 kph) as it passed near Haiti's northwestern coast, according to the U.S. National Hurricane Center in Miami.
At 11 a.m. EDT (1500 GMT), Noel's poorly organized center was about 80 miles (130 kilometers) east-southeast of Cuba's eastern tip and about 300 miles (500 kilometers) southeast of the central Bahamas, forecasters said.
It was heading north-northwest at roughly 12 mph (10 kph). A long-term forecast has the storm passing through the Bahamas and gradually turning east, away from the U.S. coastline.
Russian officials have repeatedly declared that Israeli aviation poses a threat to the Russian military in Syria.