MEXICO CITY, Dec. 17 (Xinhua) -- President Andres Manuel Lopez Obrador said on Monday that fuel theft makes Mexico lose between 2.9 and 3.9 billion U.S. dollars a year, vowing to combat the crime.

Lopez Obrador told reporters that he would soon unveil a plan to fight the growing scourge, saying "it is a serious problem because they steal between 60 and 80 billion pesos (around 2.95 and 3.93 billion U.S. dollars) a year" from state-owned pipelines.

"We have already appointed a coordinator ... and all government agencies are working together" on a strategy to tackle the problem, he said.

Fuel stealers include not only organized crime groups, but also corrupt employees of the state-owned oil company, Petroleos Mexicanos (Penex), said Lopez Obrador.

"There are indications that theft is happening inside Pemex, the refineries and the fuel distribution centers," he added.

As a first step, the president proposed making fuel theft a serious crime that entails prison time with no possibility of bail.

The crime happens mostly in the central state of Puebla, where there is a concentration of oil pipelines leading from the Gulf Coast.