热带风暴艾萨克将袭击伊斯帕尼奥拉岛
Haiti and the Dominican Republic are braced for a battering as Tropical Storm Isaac approaches Hispaniola.
海地和多米尼加共和国将遭受热带风暴艾萨克的袭击。
Some 400,000 Haitians still living in makeshift（临时的） camps after a deadly earthquake in 2010 are "amongst the most vulnerable", aid groups warn.
Isaac could have become a hurricane by the time it is due to hit the island later on Friday, meteorologists（气象学家） say.
It will then move on to Cuba and the southern US by the weekend.
The storm could pose a potential threat to Florida during the US Republican National Convention.
Disease warning
At 00:00 GMT, Isaac - with gusts of winds of 75km/h - was about 340km
south-east of the Dominican Republic's capital, Santo Domingo, the Miami-based US National Hurricane Center said.
The storm could unleash up to 20 inches (51cm) of rain when it makes landfall on the island.
"These rains could cause life-threatening flash floods and mudslides," the NHC warned.
In Haiti, people living in the makeshift squatter camps were "amongst the move vulnerable, should the storm hit the city," humanitarian group World Vision said.
"Without a stable sanitation system or permanent housing, heavy rain and wind can create much larger problems like disease from water contamination," the group's Haiti director Jean-Claude Mukadi was quoted as saying by the AFP news agency.
Isaac is also expected to bring rain and wind to the nearby Puerto Rico.