KABUL, Afghanistan -- Gunmen stormed the local headquarters of Afghanistan's state media in the eastern Nangarhar province on Wednesday, setting off clashes that killed seven people and wounded at least 18, officials said.

Interior Ministry spokesman Najib Danish said the attack began with an explosion, followed by a gun battle with Afghan security forces. He said four attackers and three people, including a police officer, were killed in the fighting, which had come to an end by the afternoon.

The Islamic State of Iraq and Syria (ISIS) claimed responsibility for the attack via its pseudo-news agency, Amaq. The Sunni Muslim extremist group has been pummelled in Nangarhar in recent months, increasingly becoming a focus of both Afghan domestic forces, and their American partners.

Two U.S. troops were killed in fighting with ISIS in Nangarhar last month, not long after the U.S. military dropped the "mother of all bombs" on an ISIS tunnel network in the province.

Get Breaking News Delivered to Your Inbox

Inhamullah Miakhial, a spokesman for the provincial hospital in Nangarhar, said it has received at least 18 wounded people.

The state media building is close to the governor's compound and a police station. Video footage from Jalalabad showed hundreds of Afghan security forces fanning out across the city, where shops were closed.

Both the Taliban and ISIS' affiliate in Afghanistan are active in Nangarhar, a mountainous province that borders Pakistan.

Elsewhere in Afghanistan, three civilians were killed in separate bomb blasts, according to officials.

Qais Qadri, spokesman for the governor of eastern Kapisa province, said two civilians were killed and two others were wounded in a bomb blast late Tuesday in the Nijrab district.

Samim Khpolwak, spokesman for the governor of the southern Kandahar province, said a civilian was killed and 10 people were wounded, including three policemen, in a double bombing in the provincial capital. No one immediately claimed either attack. The Taliban have stepped up their attacks since announcing their spring offensive last month.