JALALABAD: Militants stormed the national television and radio station in the eastern Afghan city of Jalalabad on Wednesday, triggering a gunfight as journalists remained trapped inside the building, officials and eyewitnesses said.

No insurgent group has so far claimed responsibility for the attack in Nangarhar province, a hotbed of Daesh militants, where the US military dropped its largest non-nuclear bomb last month in an unprecedented attack.

"Three gunmen entered the RTA (Radio Television Afghanistan) building this morning," government spokesman Attaullah Khogyani told AFP. "Two of them have been killed and one is still resisting."

An RTA photographer said he fled the building as soon as the gunfight erupted, but some of his colleagues were still stuck inside. An AFP reporter near the scene of the attack also heard two explosions.

Daesh insurgents are active in Nangarhar province, of which Jalalabad is the capital.

The US military last month dropped the GBU-43/B Massive Ordnance Air Blast bomb -- dubbed the "Mother Of All Bombs" -- on Daesh positions in Nangarhar, killing dozens of militants.

The unprecedented attack triggered global shock waves, with some condemning the use of Afghanistan as what they called a testing ground for the weapon, and against a militant group that is not considered as big a threat as the resurgent Taliban.

According to the US Forces-Afghanistan, defections and recent battlefield losses have reduced the local Daesh presence from a peak of as many as 3,000 fighters to a maximum of 800.

The Pentagon has reportedly asked the White House to send thousands more troops to Afghanistan to break the deadlocked fight against the Taliban.

US troops in Afghanistan number about 8,400 today, and there are another 5,000 from NATO allies, who also mainly serve in an advisory capacity -- a far cry from the US presence of more than 100,000 six years ago.

Dangers faced by media

Wednesday´s attack marks the latest militant assault on an Afghan media organisation.

Afghanistan suffered its deadliest year on record for journalists in 2016, according to the Afghan Journalists´ Safety Committee (AJSC), adding that the country is the second most dangerous for reporters in the world after Syria.

At least 13 journalists were killed last year, AJSC said, claiming that the Taliban was behind at least ten of the deaths.

In January last year, seven employees of popular TV channel Tolo, which is often critical of the insurgents, were killed in a Taliban suicide bombing in Kabul in what the militant group said was revenge for "spreading propaganda" against them.

It was the first major attack on an Afghan media organisation since the Taliban were ousted from power in 2001 and spotlighted the dangers faced by media workers in Afghanistan as the security situation worsens amid a growing wave of militant attacks.