At least 40 Taliban fighters have been killed in a gun battle with Afghan security forces that lasted for 12 hours in the southern Helmand province, according to local media reports.

The clashes erupted after the fighters attacked a local market in the centre of Gereshk district on Friday morning, TOLOnews, an Afghan news outlet, reported.

The clashes are the latest in a series of attacks to have hit Afghanistan this week.

On Thursday, at least five security officials were killed and several wounded in a Taliban-claimed car bomb attack near their checkpost, also in the Gereshk district.

One NATO soldier was killed and six other personnel - including five soldiers and an interpreter - were wounded in an attack in the Qarabagh district in Kabul province claimed by the Taliban on Thursday night.

On Wednesday, two US soldiers were killed by a suicide bomber who targeted a convoy of foreign forces in the southern Kandahar province.

Dozens of people were killed in a suicide attack at a packed Shia mosque in the western province of Herat on Tuesday.

Earlier this week, a suicide bombing and gun attack claimed by the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group on the Iraqi embassy in the capital killed two Afghan employees.

A total of 2,531 Afghan security forces were killed and 4,238 wounded in the first four months of 2017, according to the Special Inspector General for Afghanistan (SIGAR).