A Taliban attack on a military base in Kandahar province has left at least 15 Afghan soldiers dead, according to government officials.

Dawlat Waziri, Afghanistan's defence ministry spokesman, told AFP news agency on Friday that the assault happened late on Thursday.

"The Taliban launched a coordinated assault on an army base last night in Shah Wali Kot," he said.

Waziri said the fighting continued until Friday morning.

"Fifteen Afghan army soldiers were martyred and five others wounded ... but the base remains under the control of our forces," he said.

A provincial official who spoke on the condition of anonymity gave a higher death toll of 20, adding that some soldiers were missing after the attack and that the Taliban had seized four military Humvees.

The attack was the third major Taliban assault this week on the military in Kandahar.

At least 30 soldiers were killed in a similar attack in Shah Wali Kot late on Monday.

Two days later 13 soldiers died in another raid in Kandahar's Maiwand district, a provincial official told AFP.

The Taliban claimed responsibility for the attacks as their annual spring offensive intensifies and the violence expands more than 15 years after they were officially toppled from power in a US-led invasion.

Kandahar is a hub of Taliban activity, although there has been a relative improvement in security in recent years under the grip of General Abdul Raziq, the police chief and a regional commander.

Raziq, arguably the most powerful security commander in southern Afghanistan, has criticised the central government in Kabul over the growing insecurity in Kandahar, accusing them of a plot to destabilise his province.

"Some political figures within the National Unity Government are trying to destabilise Kandahar like [neighbouring] Helmand and Uruzgan provinces," Raziq told a public gathering on Thursday.

"Whenever there is an attack in Kandahar, the central government does not help."

His remarks did not immediately elicit a response from authorities in Kabul.