KABUL — Afghans are losing confidence in the direction their country is headed even though most feel more prosperous now than under the ousted Taliban regime, a U.S.-funded survey released on Thursday found.

"The number of Afghans who feel optimistic is lower than on the eve of the 2004 presidential elections," according to the survey, which was conducted by the Asia Foundation and paid for by the U.S. Agency for International Development.

Some 44 per cent of more than 6,000 adults surveyed across the country felt the country is headed in the right direction compared with the 2004 survey's finding, when 64 per cent thought that.

Corruption and bad governance, rather than the lack of security, were the biggest reasons Afghans felt their country was headed in the wrong direction, it said.

Afghanistan this year has been rocked by its deadliest violence since the ouster of the Taliban regime in the U.S.-led invasion in 2001, mostly in the south.

More than 3,000 people, mostly militants, have been killed in violence during 2006, according to an Associated Press count, based on reports from U.S., NATO and Afghan officials -- more than double the toll for all of 2005.

Still, nearly 90 per cent of those surveyed said they trusted the U.S.-trained Afghan National Army and 86 per cent trusted the police, that despite widespread reports of corruption and concerns that the police in particular are poorly trained.

"The findings of the survey challenge some common perceptions about what is out there," said the foundation's George Varughese, who led the survey.

"For example you'd think that security would be the foremost of concerns. We find that it is indeed, but only in the south. In the north it isn't," he said, adding that economic insecurity was the foremost concern of most Afghans.

Some 54 per cent of respondents felt that they were "currently more prosperous" than under the Taliban regime -- when Afghanistan was internationally isolated and faced sanctions. Only 26 per cent felt less prosperous and 12 per cent reported no change.

The foundation said the survey, conducted in all but two of the country's 34 provinces, was the largest comprehensive opinion poll ever conducted in Afghanistan. Some 6,226 people aged 18 years and over were interviewed between June and August. The margin of error was 2.5 per cent, it said.

Respondents identified the main problems facing Afghanistan as its poor economy, security, the slow pace of reconstruction, poor government performance and corruption.

Some 80 per cent felt that cultivation of opium poppies was wrong, but less than 10 per cent linked the trade to terrorism, insecurity and corruption in the country, it said.

Afghanistan accounts for over 90 per cent of the world's supply of opium, the substance used to make heroin. Cultivation of opium rose nearly 60 per cent last year, and police and government officials profit from the trade.

Life expectancy among Afghanistan's 30 million people is only 43 years and about half of the population live in poverty, despite a huge injection of foreign aid in the past five years. Its maternal and infant mortality rates are among the world's worst.