KANDAHAR, Afghanistan -- Taliban gunmen surrounded a police compound in the volatile southern province of Helmand after killing 19 policemen and seven soldiers in an ongoing siege, a senior police officer said on Monday from inside the compound.
Napas Khan, the police chief in the Naw Zad district, told The Associated Press by telephone that the insurgents had advanced to within 65 feet of the compound after seizing police vehicles and weapons and blocking all roads out of Naw Zad.
"We need an immediate response from the government," Khan said.
He said the attack started at before dawn on Monday when the insurgents overran multiple police checkpoints across the district.
"They destroyed or captured most of our checkpoints and now they have reached our police headquarters," Khan said. "They are mostly firing at us from the hills overlooking our compound."
As Khan spoke, gunfire and shouting could be heard in the background.
Helmand has long been a heartland for the Taliban, who profit heavily from opium produced in its fertile river valley.
Government forces launched an operation against the insurgents in March, in the hope of reducing the impact of the Taliban's annual warm weather offensive. Since that offensive was launched in late April, however, attacks across the country have intensified, spreading government forces thin.
As well as the time-worn guerrilla-style tactics of fight-and-run, the insurgents have also stepped up suicide attacks and, in some areas, targeted assassinations and kidnappings.
Also on Monday, a suicide truck bomb attack and a separate roadside bombing in southern Afghanistan killed 11 people and wounded dozens more, as the Taliban clashed with supporters of the Islamic State of Iraq and Syria (ISIS) up in the west, officials said.
Gov. Asif Nang said the Taliban have been clashing with rival insurgents claiming allegiance to ISIS for three days in the western Farah province, leaving at least 10 Taliban fighters and 15 ISIS supporters dead. He provided no further details.
The clashes provide the latest indication of a small but growing ISIS presence in the country. Afghan and foreign officials differ over the extent to which the extremist group, which rules large parts of Syria and Iraq, is able to operate in Afghanistan, where the Taliban have been waging war against the Western-backed government for more than a decade.
The truck bomb struck the gate of the provincial council's compound in the capital of Zabul province, killing at least five people and wounding 62, council director Atta Jan Haqbayan said.
Three of the wounded were council members, Haqbayan said. Mirwais Noorzai, Zabul's police chief, said the attacker used a small truck.
President Ashraf Ghani condemned the attack. No group immediately claimed responsibility.
Insurgents have stepped up attacks in recent months in Zabul, which borders Pakistan, and a number of Hazara Shiite men have been abducted in the province.
Later on Monday, a roadside bomb exploded in neighboring Kandahar province, killing six people, according to the governor's spokesman, Samim Khopalwaq.
Three policemen were killed elsewhere in Kandahar when a firefight erupted between two groups of officers, said provincial police spokesman Zia Durrani. Four officers fled the scene, he said, adding that the incident was under investigation.
Meanwhile, in northern Sari Pul province, police said the body of a local official in charge of religious affairs, Abdul Wodod, was found Monday, three days after he was kidnapped. Gen. Habib Gulbhary, the provincial police chief, said the man was abducted by unknown assailants.