KABUL, Afghanistan (AP) — An Afghan official says 26 soldiers have been killed in a blistering Taliban assault on an Afghan National Security base in southern Kandahar province.

Mohammad Radmanish, defense ministry's deputy spokesman, said Wednesday the Taliban assault overnight in Khakrez district left another 13 soldiers wounded.

Kandahar is considered the spiritual heartland of the Taliban.

In previous reports the U.S. Special Inspector General for Reconstruction (SIGAR) has called the casualty rate among Afghanistan's National Security Forces "shockingly high." Last year more than 6,800 were killed and another 12,000 wounded according to a SIGAR report earlier this year.

The Afghan military and security forces number 195,000 soldiers and more than 150,000 policemen. They have struggled to contain the insurgency, which has stepped up attacks across the country.