BELIZE CITY (Reuters).- Flash floods caused by tropical storm Arthur have killed at least five people in southeastern Belize, including a toddler, the government of the tiny Central American country said on Wednesday.

Arthur, the first storm of the year in the Atlantic, dumped over 11 inches of rain across Belize this week as it moved inland, also drenching southern Mexican states.

The body of a 2-year-old boy was found on Tuesday evening. His father had struggled for half an hour in turbulent floodwaters before the infant was washed away.

Two people from the southeastern district of Stann Creek were still missing on Wednesday.

Belize, wedged between Mexico and Guatemala with a population of just 300,000, is best known for its laid-back atmosphere, palm-fringed islands and coral reefs.

Torrential rains from Arthur -- which have also left swathes of southern Mexico waterlogged -- swelled rivers in Belize and wiped away two bridges in the south, severing key transport arteries for Belize's farming and fishing industries.

"This was really a kind of freak occurrence that with the best will in the world, and all the resources in the world, we could not have anticipated," Prime Minister Dean Barrow, who became Belize's first black leader on taking office in February, said this week.

Authorities estimated that 13,000 people across the country were affected by Arthur.

(Reporting by Adele Ramos; Editing by Eric Walsh)