FIROZ KOAH, Afghanistan - At least 16 people were killed and 90 others wounded after a powerful explosion rocked outside a provincial police office in Firoz Koah, capital of Afghanistan's western Ghor province on Sunday, a local official confirmed.

"The final number of casualties would be shared with media later in the day. The number of casualties may change as the rescue of victims from under debris is continuing," Abdul Latif Rahimi from the provincial health directorate told Xinhua.

Many wounded remained in critical condition, he said.

The blast occurred roughly at 11:15 am (local time) when an explosive-laden minibus was detonated along a road in an area where the provincial police department and several other government offices are located, a security official who declined to be named told Xinhua.

"The nature of the blast could be a suspected suicide bombing. The blast sent a column of thick smoke into the sky and triggered panic, besides causing destruction," he said.

Security forces have cordoned off the area for precautionary measures.

No group has claimed responsibility for the attack yet.