Taliban militants have killed at least 15 Afghan soldiers during an attack on an army base in Afghanistan's southern province of Kandahar.

Dawlat Waziri, a spokesman for the Afghan Defense Ministry, said on Friday that the militants “launched a coordinated assault on an army base last night (Thursday) in the Shah Wali Kot district of Kandahar province.”

"Fifteen Afghan army soldiers were martyred and five others wounded," he added.

However, a provincial official, who asked not to be named, put the death toll at 20.

The assault is the second of its kind in less than a week.

At least 10 Afghan soldiers were killed in a Taliban attack on the Achakzai camp of army corps 205 in the same district on May 22.

The number of Taliban attacks across Afghanistan climbs every spring, when the militants increasingly target government officials and US-led foreign forces in the country. Many ordinary people often fall victim to such attacks as well.

Over 1,000 members of Afghan security forces as well as over 700 civilians have been killed so far this year, according to Afghan authorities and figures cited by the US-based Congressional watchdog Special Inspector General for Afghanistan Reconstruction (SIGAR).       

The US military is considering whether to deploy 3,000 to 5,000 more military advisers to help train and assist Afghan security forces battling a 16-year militancy by the Taliban.

The United States and its allies invaded Afghanistan in 2001. The invasion did remove the Taliban from power, but has failed to stop its terror campaign to this day.