The U.S. government is rushing relief supplies to Guyana (search), the U.S. ambassador said Saturday, after heavy rains and flooding that have killed at least six people and displaced thousands of others.

Drainage pumps, food and other supplies were expected to arrive as early as next week, U.S. Ambassador Roland Bullen (search) told The Associated Press in a telephone interview.

The Defense Force, meanwhile, was standing by to evacuate as many as 20,000 people from towns east of the capital, Georgetown, said Brig. Gen. Edward Collins, the army chief.

More than 40 inches of rain have fallen in the former British colony since Dec. 26, with more than 27 inches this month. About 8 inches is normal for January.

President Bharrat Jagdeo (search) has said the floods have affected more than half the population of 750,000. Most Guyanese live on the low-lying coast. He has appealed to the U.S. Southern Command to have U.S. troops bring in power generators and small boats.

Waters were rising in several towns, suggesting two dams east of Georgetown were spilling over, officials said. Another dam northwest of the capital also was in danger of bursting.

Collins said residents could be moved to a military camp about 30 miles south of Georgetown. The evacuation could come as early as next week.

"We are just waiting on the order, but we are ready," he said.

In some western districts of the capital, engineers worked with residents to seal more than a dozen breaches in a dam where torrents of black water had poured onto farmlands.

Many farmers said they expect to lose cassava and fruit trees.

"I am living in one room and my 59 chickens (are) in another," said farmer Pamela Persaud, 51.

The heaviest rains in a century already have forced thousands of people from homes in Georgetown and coastal villages. Most are staying with friends or relatives, though at least 5,000 are sheltering in schools, churches and public buildings.

While prices on basic goods and transportation more than quadrupled, the government and aid agencies hurried to distribute 5,000 blankets and thousands of hygiene kits. Volunteers were also delivering water and preparing meals, mostly for children and the elderly.

Authorities were still asking for boats to ferry food deep into isolated villages and to evacuate the sick and elderly from snake-infested waters.

At least six people have been killed, including three people whose bodies were found floating outside their homes Saturday and a six-year-old boy who drowned Thursday.

Brazil, which neighbors Guyana to the south, has flown in 16 tons of food and other supplies and has promised more next week.