Fighting between the Taliban and Afghan government forces resumed Sunday in the restive southern province of Helmand, officials said, ending a three-day ceasefire agreed by the warring sides to mark the Eid al-Fitr holiday.
Violence has soared as the United States military presses ahead with a plan to withdraw all of its troops by September, bringing an end to a 20-year military operation in Afghanistan.
"The fighting started early today and is still ongoing," Attaullah Afghan, head of the Helmand provincial council, told AFP as a three-day temporary truce ended late on Saturday.
He said Taliban fighters attacked security checkpoints on the outskirts of Lashkar Gah, the capital of Helmand province, and some other districts.
An Afghan army spokesman in the south confirmed fighting had resumed, and the Helmand governor's office said that 21 Taliban fighters had been killed so far.
"They (Afghan forces) started the operation... do not put the blame on us," Taliban spokesman Zabihullah Mujahid told AFP.
The US has vowed to end America's longest war but missed a 1 May deadline to pull out, as agreed with the Taliban last year in return for security guarantees and a promise to launch talks with the Afghan government.
President Joe Biden pushed back the date to 11 September - exactly two decades on from the terrorist attacks in the United States which led the US to invade Afghanistan and oust the Taliban.
Tens of thousands of Afghans have been killed and millions have since been displaced by the conflict, which has seen a resurgent Taliban take hold of large swathes of the country.
The three-day truce initiated by the Taliban and swiftly agreed to by the Afghan government had largely held during the Eid holidays that ended on Saturday.
The calm was, however, broken on Friday by a blast at a mosque on the outskirts of the Afghan capital, which killed 12 people including the imam leading Friday prayers.
The Taliban denied it was behind the attack, which has been claimed by IS, according to the SITE Intelligence Group, which monitors jihadist groups.
The truce was only the fourth agreed pause in fighting in the two-decades-long conflict.
The warring sides launched unprecedented peace talks in September in Qatar, but they have stalled in recent months.
