Afghan authorities say they are trying to track down a radio station -- allegedly established by the Islamic State (IS) extremist group -- that is spreading antigovernment propaganda in eastern Nangarhar Province.
Broadcasting in Pashto, the Voice of the Caliphate encourages young Afghans to join the ranks of the militant group and take up arms against the government in Kabul.
The broadcasts are adding to concerns about the situation in Nangarhar, where a top U.S. general said this week that IS allies in Afghanistan are trying to establish a regional base. Reports on December 17 said fighters pledging loyalty to IS had overrun new areas in Nangarhar.
Nangarhar officials say the FM station's strong signal reaches the provincial capital, Jalalabad -- strategically located near the Khyber Pass on a major trade and transport route linking Afghanistan and Pakistan -- and nearby districts in Afghanistan's volatile east.
It's not clear when the broadcasts began, but Afghanistan's Ministry of Communications and Information Technology said on December 17 that it found about the station "around two weeks ago."
Spokesman Yasin Samim said authorities "are working to establish the station's location."
However, "it's not an easy task given the lack of security" in the volatile area that borders Pakistan's restive tribal regions, he said.
"It's not being broadcast on an Afghan radio frequency," Samim told RFE/RL's Radio Free Afghanistan.
Samim stopped short of confirming a claim by the Nangarhar provincial government that the Voice of the Caliphate is being broadcast from neighboring Pakistan.
"We need to wait until it's clearly established [by specialists]," Samim said.
"It's possible that the radio station's technical capabilities were provided by a neighboring country or, alternatively, that it is being broadcast via small, portable transmitters."
However, the office of the Nangarhar governor says it has requested the Pakistani Consulate in Jalalabad take measures to take the radio station off the air.
"According to our information, the radio is being broadcast from the other side of the border," said Asadullah Khugyani, the governor's spokesman.
"The militants use social media, such as Facebook, and the radio to spread their message," he said.
Afghan authorities have voiced concerns over the growing presence of militants loyal to IS in the conflict-torn country.
A deadly suicide bombing that killed at least 35 people and wounded more than 100 others outside a Jalalabad bank in April was claimed by Islamic State, which seized swaths of Iraq and Syria last year.
The bombing, the first major attack claimed by the militant group in Afghanistan, prompted President Ashraf Ghani to warn of what he described as the "terrible threat" posed by IS extremists to "the states of western and central Asia."
The commander of U.S. and NATO forces in Afghanistan, John Campbell, said earlier this week that "foreign fighters" from Syria and Iraq had joined Afghan militants, who declared loyalty to the IS group in Nangarhar.
Campbell also said there were "indications" that the IS loyalists in Nangarhar were seeking to establish links with the Sunni extremist group's leadership in Syria and Iraq.
According to Campbell, there are currently 1,000 to 3,000 IS members active in Afghanistan.
He said many dissatisfied Taliban have rebranded themselves as IS, in a likely "attempt to attract media attention, solicit greater resources, and further increase recruitment."
Nangarhar authorities arrested 27 students in Jalalabad in November amid media reports that IS flags were raised during student protests over living conditions in university dormitories.
The IS group also publishes an online English-language magazine, Dabeq, and runs a radio network in Iraq in several languages, including Arabic, English, and Russian.
The group also frequently publishes gruesome video recordings that document the militant group's atrocities, including beheadings of hostages, setting them on fire inside cages, and throwing them off buildings.
Written by Farangis Najibullah based on reporting by RFE/RL Radio Free Afghanistan correspondent Zhakfar Ahmadi
