Taliban militants attacked an Afghani army base, killing at least 15 soldiers following similar assaults earlier this week.

The Defense Ministry said that the attack took place in the Shah Wali Kot in the southern province of Kandahar.

The attack late Thursday came just three days after 10 Afghan soldiers were killed when Taliban militants stormed another base in the same area.

“The Taliban launched a coordinated assault on an army base last night (Thursday) in Shah Wali Kot district of Kandahar province,” ministry spokesman Dawlat Waziri told AFP.

“Fifteen Afghan army soldiers were martyred and five others wounded.”

Waziri said the insurgents were driven back and 20 of their fighters killed. There was no immediate response from the Taliban.

A provincial official who spoke on the condition of anonymity gave a higher death toll of 20.

The attack comes as Taliban insurgents intensify their annual spring offensive and their strength is growing, more than 15 years after they were toppled from power in a US-led invasion.

It highlights a growing insurgent offensive in Kandahar, where security has relatively improved in recent years under the leadership of police chief and regional strongman General Abdul Raziq.

Raziq had lashed out at the central government in Kabul on Thursday, accusing them of a plot to destabilize his province.

“Some political figures within the National Unity Government are trying to destabilize Kandahar like (neighboring) Helmand and Uruzgan provinces,” Raziq told a public gathering.

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

Also on Thursday, a suicide car bomber detonated his explosives at a security post in southern Helmand province killing three intelligence officials, a police spokesman said.

The attack also wounded four intelligence officials, said the spokesman, who gave his name only as Zaman. The provincial governor’s spokesman, Omar Zwak, confirmed the attack.

The Taliban in a statement claimed responsibility, saying the explosion killed Tor Jan, intelligence director for the Washer district in Helmand.

In western Badghis province on Wednesday, Taliban fighters attacked security checkpoints, killing six security forces, said Anwar Ishaqzai, provincial governor. He said five others were wounded, while 16 Taliban militants were killed in the fight with government forces.

The attacks mark another setback for NATO-backed Afghan forces. They come just a month after the Taliban killed at least 135 soldiers in the northern province of Balkh in the deadliest insurgent attack on an Afghan military base since 2001.

And in another deadly Taliban attack on security outposts in southern Zabul province on Sunday, local officials made desperate calls to Afghan television stations to seek attention because they were unable to contact senior authorities for help.

The battlefield losses have raised concerns about the capacity of Afghan forces, beset by unprecedented casualties and blamed for corruption, desertion and “ghost soldiers” who exist on the payroll but whose salaries are usurped by fraudulent commanders.

The Taliban launched their annual “spring offensive” in late April, heralding a surge in fighting as the US tries to craft a new Afghan strategy.

US Defense Secretary Jim Mattis last month warned of “another tough year” for security forces in Afghanistan.

The United States and several NATO allies are considering sending thousands more troops to break the stalemate against the resurgent militants.