KABUL - The Afghan Taliban militants on Friday announced the start of their yearly rebel offensive in Afghanistan as fighting rages in the country.

The group has codenamed their offensive "operation al-Fath", or operation of victory, according to a statement shared with media by Zabiullah Mujahid, a purported Taliban spokesman.

The Taliban frequently starts the yearly offensive in spring. Fighting between government forces and Taliban fighters often gets intense in spring and summer as the seasons are locally branded as the fighting time of year.

The statement came as daily violence and clashes have been continuing in the country.

On early Friday, two police officers were killed and one police wounded after militants stormed a security checkpoint on outskirts of Ghazni city, capital of eastern Ghazni province, provincial police spokesman Ahmad Khan Serat told Xinhua.

Several militants were also killed and wounded during the gun battle, but their number could not be exactly specified as the militants evacuated their casualties after the fighting.

The militants, who ruled the country before being ousted in late 2001, renewed armed insurgency, killing government troops as well as civilians.

They urged civilians to stay away from official gatherings, military convoys and centers regarded as the legitimate targets by militants besides warning people not to support the government.

Since Jan 1, 2015, Afghan security forces have assumed the full security charges from NATO and US forces.

Around 16,000 foreign troops have remained in Afghanistan to train and assist local security forces in their fight against the insurgents.