MAZAR-I-SHARIF • Afghanistan observed a national day of mourning yesterday after at least 100 soldiers were killed or wounded in a Taleban attack on a military base, prompting angry calls for ministers and army chiefs to resign.

The exact toll from Friday's assault in the northern province of Balkh remains unclear. Some local officials say as many as 130 died.

The five-hour assault, the deadliest ever by the group on a military base, underscores its growing strength more than 15 years after it was ousted from power.

Flags flew at half-mast throughout the country, and special prayers were said for the dead.

The defence ministry gave a figure of at least 100 soldiers killed or wounded. But local officials, including provincial council head Mohammad Ibrahim Khairandish, put the death toll as high as 130 and said about 60 were wounded.

Ten gunmen in soldiers' uniforms, armed with suicide vests, entered the base in army trucks and opened fire on unarmed troops at close range.

Ordinary Afghans vented their anger at the government for its inability to counter a series of brazen Taleban assaults, including a raid on the country's largest military hospital in Kabul in March that left dozens dead.

"Mothers lost their sons, sisters lost their brothers, and wives lost their husbands. What is the government doing to prevent such atrocities, only condemning? I am so tired, I can't do anything but cry," a user called Zabiullah posted on Facebook.

"The best way to honour them is to fire and punish those who failed to do their jobs and/or cooperated with the enemy. Some leaders must go!" said a Twitter user.

Many called for the resignation of Defence Minister Abdullah Habibi and the commander of the 209th Corps stationed at the base.

A military source at the base indicated that the assault was an insider attack, and that the militants were "young recruits who had come for training".

Taleban spokesman Zabihullah Mujahid said on Saturday the attack was retribution for the recent killing of Taleban leaders in northern Afghanistan. The United States military command in Kabul said an American air strike had killed a commander, Quari Tayib, and eight other Taleban last Monday.

Mujahid said the attack on the base killed up to 500 soldiers, and four attackers were Taleban sympathisers who had infiltrated the army and served for some time. The army did not confirm that.

Afghan troops and police have struggled to beat back insurgents since US-led Nato troops ended their combat mission in 2014.

AGENCE FRANCE-PRESSE, REUTERS