BOGOTA: Rescuers were working against the clock to rescue 11 people trapped in a flooded illegal goldmine since last week, Colombian authorities said Monday.

The group has been trapped since last Friday in a 17-meter (55-foot) deep shaft flooded in a heavy downpour.

According to the National Mining Agency (ANM), rescuers were using electric pumps to remove water from the mine.

"Eleven people are still missing," Luis Velasquez, governor of the northwestern Caldas department, told reporters. "We hope that in less than 48 hours" they will have been rescued.

Diego Mesa, minister of mines and energy, said the missing miners had been involved in "unauthorized" activity.

Accidents of this type are common in Colombia, where income from illegal gold mining exceeds that from drug trafficking -- two practices that funded armed groups fighting a near six-decade conflict Colombia is still recovering from.

So far this year, 33 illegal miners have died, according to the ANM, and 171 last year.

Legal mining and oil are the main exports of Latin America's fourth-largest economy.