KANDAHAR, Afghanistan -- Taliban gunmen have overrun a strategic district in the southern province of Helmand, delivering a serious blow to government forces, Afghan officials said on Monday.
Fierce fighting in the Sangin district was continuing after the insurgents took control late Sunday, said Mohammad Jan Rasulyar, Helmand's deputy governor.
Only Afghan army facilities in the district had not been taken by the insurgents, he said. Casualties among Afghan security forces were high, he added, though he gave no figures.
Rasulyar on Sunday took the unusual step of using his Facebook page to warn President Ashraf Ghani that Helmand was in danger of falling if central authorities failed to send help.
Afghanistan's Chief Executive Abdullah Abdullah met with security advisers early Monday and urged "immediate action," his deputy spokesman Javid Faisal said. Faisal said Afghan forces had launched a counter-offensive to retake control of the district.
More than 90 members of the Afghan security forces died fighting in the past month, with hundreds killed in the past six months, he said in his open letter to Ghani.
Helmand is an important Taliban base as it produces most of the world's opium, a crop that helps fund the insurgency.
The head of Helmand's provincial council, Muhammad Kareem Atal, said that 28 members of the Afghan security forces - usually a reference to army and police who also fight on the front lines across the country - were killed fighting on Sunday. Another 15 were critically wounded, he said.
"Around 65 percent of Helmand is now under Taliban control," Atal said.
"In every district either we are stepping back or we are handing territory over to Taliban, but still, until now, no serious action has been taken," he said, echoing Rasulyar's plea to the central authorities for help.
He said more than 2,000 members of the security forces had been killed fighting in Helmand in 2015.