AKIPRESS.COM - The Afghan Taliban said their annual "spring offensive" will begin on Friday, vowing nationwide attacks in what is expected to be the bloodiest fighting season in a decade as NATO forces pull back from the frontlines, the media reports say Wednesday.

This year's offensive marks the first fighting season in which Afghan security forces will battle the insurgents without the full support of US-led foreign combat forces.

The militants have already stepped up attacks on government and foreign targets in recent weeks, taking a heavy toll on civilians and Afghan security forces.

"The Islamic Emirate is going to launch the spring operations under the inspirational name of 'Azm' (determination) at 5 am on 24th April 2015," the Taliban said in a statement on Wednesday, using their official name.

"The main targets of these operations... will be the foreign occupiers, especially their permanent military bases... officials of the stooge regime, their military constellations, especially their intelligence, interior ministry and defence ministry officials."

NATO's combat mission formally ended in December but a small follow-up foreign force has stayed on to train and support local security personnel.