DAKAR, Senegal (AP) — Extortion at security checkpoints is costing Ivory Coast millions each year despite government steps to eradicate the practice, a rights group said Wednesday.

Four years after Ivory Coast President Alassane Ouattara's government said it would stop security forces from demanding money at roadblocks from travelers, including merchants transporting goods and immigrants, it is still costing the economy $340 million CFA ($567 million), Human Rights Watch said in a new report citing World Bank figures.

"While there has been some progress over the last few years, President Ouattara's government hasn't done enough to end checkpoint extortion," said Jim Wormington, West Africa researcher at Human Rights Watch. "Security forces continue to enrich themselves at the expense of ordinary Ivorians, many of whom are already struggling to earn enough to make ends meet."

Government spokesman Bruno Kone could not immediately be reached for comment on the report.

The practice seems well-organized, HRW said, as officials truck drivers' registration numbers. If they refuse to pay, they can be detained.

"If you don't pay, it's a fight. If you don't give him his share, it's a fight," a taxi driver told the rights group. His name was not given. For immigrants, it's more difficult. They hand over their papers and must pay to get them back, or "validated" the group said.

Extortion, though illegal, remains rampant because the money is often passed up the chain of command, the group said. Wormington called on the government to work harder to investigate and prosecute violators.

Associated Press writer Isidore Kouadio in Abidjan, Ivory Coast contributed to this report.