FILE - In this Oct. 26, 2016 file photo, Afghan men gather around the bodies of several civilians who were killed by Taliban fighters in Ferozkoh, Ghor province, Afghanistan. Afghanistan's Taliban announced the start of their spring offensive Friday, April 28, 2017, promising to build their political base in the country while focusing military assaults on coalition and Afghan security forces. (AP Photo, File)
FILE - In this Oct. 26, 2016 file photo, Afghan men gather around the bodies of several civilians who were killed by Taliban fighters in Ferozkoh, Ghor province, Afghanistan. Afghanistan's Taliban announced the start of their spring offensive Friday, April 28, 2017, promising to build their political base in the country while focusing military assaults on coalition and Afghan security forces. (AP Photo, File)

The Afghan Taliban announced the beginning of their spring offensive on Friday, promising to build their political base in the country while focusing military assaults on the international coalition and Afghan security forces.

Taliban spokesman Zabihullah Mujahid announced the launch of the offensive in an emailed statement that boasted of Taliban control over more than half of the country, referring to a February report issued by Washingtonโ€™s special inspector general for Afghan reconstruction.

That report said the Afghan government had control or influence over only 52 percent of Afghanistanโ€™s 407 districts last year, down from 63.4 percent previously.

The Taliban dubbed this yearโ€™s offensive โ€œOperation Mansouri,โ€ named for the Taliban leader killed last year in a U.S. drone strike.

โ€œHence, keeping the evolving situation in mind, this yearโ€™s Mansouri operations will differ from previous ones in nature and will be conducted with a twin-tracked political and military approach,โ€ said Mujahid. He did not make any mention of peace talks with the government.

Attempts to find a peaceful end to Afghanistanโ€™s protracted war have been relentlessly unsuccessful.

On the political side, Mujahid said the Taliban were going to begin building institutions in areas under their control, establishing what he called โ€œsocial justice and developmentโ€ mechanisms.

He didnโ€™t offer specifics or indicate whether this meant the Taliban would step up their brand of justice, which during their rule included public executions and the chopping off of hands for those convicted of theft.

Recent Taliban attacks, including one earlier this week on an army base in northern Afghanistan that killed more than 140 Afghan soldiers, would seem to warn of a tough fighting season ahead. In the latest attack, the Taliban disguised as Afghan army soldiers slipped into the compound of the 209 Corps in northern Afghanistanโ€™s Balkh province. While two militants exploded their suicide vests, the others opened fire on scores of soldiers.

As well as the Taliban, Afghanistan is also battling an emerging local affiliate of the Islamic State group known as Islamic State in Khorasan, which is an ancient name for a region that once included Afghanistan, Iran and parts of Central Asia.

On Thursday two U.S. Army Rangers were killed and a third incurred minor injuries during a battle against Islamic State fighters in their stronghold in eastern Afghanistanโ€™s Nangarhar province, according to the U.S. military.