Taliban gunmen have surrounded a police compound in Helmand province after killing 19 policemen and seven soldiers in a continuing siege, police say.
The insurgents advanced to within 20 metres of the compound, seized police vehicles and weapons and blocked all roads out of Naw Zad district.
"We need an immediate response from the government," Napas Khan, the police chief in the Naw Zad told the Asscoiated Press in a phone call from inside the compoung .
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, however, in late April, attacks across the country have intensified, including 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 group in the west, officials said.
The Taliban have been clashing with rival insurgents claiming allegiance to the IS group for three days in the western Farah province, leaving at least 10 Taliban fighters and 15 IS supporters dead, an official said.
The clashes provide the latest indication of a small but growing Islamic State presence in the country.
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. President Ashraf Ghani condemned the attack. No group immediately claimed responsibility.
Later on Monday, a roadside bomb exploded in the neighbouring Kandahar province, killing six people.