KABUL (Reuters) - American and Afghan forces have expanded their air strikes against drug labs into western Afghanistan, aiming to choke Taliban revenue.

Air strikes in Afghanistan, the world’s main heroin source, also threaten civilians, however, and may not be an effective blow to the Taliban militant group, an expert on the country’s drug industry said.

The campaign targeting Afghan drug labs began as opium production jumped 87 percent last year to a record high in Afghanistan. The Taliban, which U.S. officials say controls the drug trade, has made large territorial gains since a U.S. troop reduction of recent years.

American and Afghan forces responded with a dramatic increase in air power since early 2017, with the number of weapons released tripling in the first two months of 2018 compared with a year earlier.

U.S. Forces-Afghanistan (USFOR-A) and Afghan forces conducted strikes on 11 Taliban drug production facilities in the western provinces of Farah and Nimroz this week, U.S. Forces said on Saturday. The strikes are the first in western Afghanistan and aim to reduce the Taliban’s main revenue flow, the U.S. statement said.

“By cutting off the Taliban’s economic lifelines, we also reduce their ability to continue these terrorist activities,” said Major-General James Hecker.

Drug processing and taxation generate $200 million annually for the Taliban, U.S. Forces-Afghanistan estimates.

The drug lab campaign began in November, and has now included 75 strikes, especially in Helmand, the main poppy-growing province. The poppy’s fluid, opium, is processed into heroin.

However, David Mansfield, an authority on Afghanistan’s opium industry, says bombing labs has a negligible effect on Taliban revenues, because heroin profits and taxes are not as large as U.S. Forces estimate and the simple labs can be quickly rebuilt.

Calling strikes on drug labs “the theater of counter-narcotics,” Mansfield said the risk of civilian deaths may be greater than potential benefits of curbing Taliban revenues.

“There has been little account of the number of casualties attributed to the bombing of drugs labs,” he said in an email to Reuters. “And in contrast to the narrative of USFOR-A, those that work in labs are not seen as Taliban but as civilians” by rural Afghans.

No civilian casualties have resulted from the campaign, said Colonel Lisa Garcia, spokeswoman for USFOR-A, adding that it also involves targeting financiers and logistics connected to drug production.

“While the narco-heroin producing labs may be replaced, we can strike them as fast as they re-appear,” Garcia said. “Destroying support networks have degraded the Taliban insurgency, and they are on the defensive.”

Taliban spokesman Qari Yousaf Ahmadi denied that the militancy depends on drug revenue, adding that when it previously formed a government it banned narcotics. He blamed U.S.-led foreign forces for Afghanistan’s growth in poppy cultivation, alleging that U.S. commanders promoted it.