FACTBOX - Key facts about Zimbabwe's crisis

(Reuters) - Zimbabwe, which at independence from Britain in 1980 was one of Africa's richest and most developed countries, has seen its economy all but collapse amid continued political tensions over President Robert Mugabe's rule.

Mugabe, 83, blames sabotage by political enemies and Western critics, while his opponents say his government is responsible for poor economic management and widespread corruption.

Following are five facts about Zimbabwe's crisis:

- Annual inflation is now at 1,700 percent, the highest in the world. The International Monetary Fund predicts it could reach 4,000 percent by the end of the year. There are regular shortages of food, fuel and foreign exchange.

- Unemployment is running about around 80 percent, and an estimated 3.5 million of Zimbabwe's 12.5 million people have fled the country looking for work, most of them to South Africa.

- Average life expectancy is now less than 37, the lowest in the world. The country is among the worst hit by Africa's HIV/AIDS pandemic, with HIV prevalence now at about 18.1 percent of the adult population.

- Production of the staple maize crop has dropped sharply following the government's seizure of white-owned farms to give to landless blacks beginning in 2000. Once the region's breadbasket, Zimbabwe is forecast by the U.S. Department of Agriculture to produce just 850,000 tonnes of maize this year, or less than half of its domestic needs.

- Mugabe and other senior members of his ruling ZANU-PF party remain under U.S. and European sanctions following allegations of poll fraud beginning in 2000. Mugabe has nevertheless said he would be willing to stand again in elections as early as next year, which could keep him in office through 2014.