Who are the Haqqanis, Afghanistan's most feared insurgents?

Afghanistan President Ashraf Ghani announced on Tuesday (12) that he will free Anas Haqqani, the brother of a feared militant leader whose eponymous group is considered one of the most dangerous factions fighting Afghan and US-led NATO forces in Afghanistan.

The release of Haqqani and two other high-ranking Taliban prisoners appears to be part of a potential prisoner swap for American Kevin King and Australian Timothy Weeks, professors at the American University of Afghanistan who were dragged from vehicles in Kabul by gunmen in 2016.

- Who is Anas Haqqani? -

Anas Haqqani's older brother Sirajuddin heads the Haqqani Network, a Taliban affiliate founded by their father Jalaluddin and blamed for some of the most shocking and brutal attacks in Afghanistan since the US invasion of 2001.

He was arrested in 2014 and sentenced to death in 2016, with Afghan authorities accusing him of a being a high-level player in the network. The Taliban has long demanded his release, insisting he is a student.

Speculation he might be freed in return for Taliban concessions has swirled repeatedly since then -- especially since the US began holding direct talks with the insurgents last year.

His fate has also been seen as a bargaining chip in negotiations over various Western hostages -- as in 2016 when rumours swirled in Kabul that the government was planning to execute him.

Shortly after, the militants released a video showing Canadian Joshua Boyle and his American wife Caitlan Coleman, who were kidnapped in 2012, pleading for their release. They were freed the following year.

- Does his release affect talks? -

Over the past year Washington and the Taliban have been holding direct talks, seeking an agreement that many hoped would pave the way for US troops to begin leaving Afghanistan and for the militants to start negotiations with Kabul.

They were on the verge of a deal when US president Donald Trump scuttled the talks in September, citing Taliban violence.

Most observers agree that a political settlement is the only way towards lasting peace in Afghanistan, and both the US and the Taliban left the door open for talks to resume.

The release of Anas Haqqani could indicate a breakthrough of sorts.

The Taliban had included his name in a negotiating team unveiled in February, and the group's spokesman said at the time that he had been captured by the Americans, and "should be released to better help with the talks".

On Tuesday Ghani said the decision to free him and the other prisoners had been taken in part to "pave the way for holding direct talks with the Taliban".

- Why are the Haqqanis so important? -

The group was founded by Jalaluddin, who gained notoriety during the mujahideen war against the Soviet occupation in the 1980s. At first a valuable CIA asset, he also fostered close ties with foreign jihadists including Osama bin Laden.

He later became a minister in the Taliban regime before launching an insurgency against foreign forces after the US-led invasion of 2001.

A designated terror group long suspected of links to Pakistan's shadowy military establishment, the network was described by US Admiral Mike Mullen in 2011 as a "veritable arm" of Pakistani intelligence.

Jalaluddin's death was announced last year and the network is now led by his son, Sirajuddin, who doubles as the Afghan Taliban's deputy leader.

The Haqqanis are known for their frequent use of suicide bombers and analysts suspect them of being behind some of the high-profile Kabul attacks claimed by the Islamic State group in recent years.

Among many grim assaults, they were accused of killing around 150 people in the heart of the capital with a truck bomb in May 2017, though Sirajuddin later denied responsibility in a rare audio message.

The network has also been accused of assassinating top Afghan officials, and kidnapping Westerners for ransom.

The Haqqanis long held US soldier Bowe Bergdahl, who was released in 2014 in exchange for five Afghan Guantanamo Bay detainees.

- Where are the Haqqanis now? -

Following the US invasion of Afghanistan, Taliban fighters including the Haqqanis flooded across the border into Pakistan, where they regrouped before launching an insurgency.

The US launched repeated drone attacks against the group, while Pakistan's military conducted successive clearing operations and now insists that there are no militant safe havens left on Pakistani soil.

Some militant sources say the pressure forced many of the Haqqanis underground or over the border, back into their Afghan strongholds, claims that cannot be confirmed.

Unverified reports placed Jalaluddin in Pakistan in the years before he died. It is not yet clear where Anas will go once he is released.