In one of Afghanistan's biggest cities, the radical message of the Islamic State (IS) resonates from radio sets.
"With Allah's help, we will plant our black flag over the Arg [presidential palace] in Kabul and the seats of government in Islamabad," an unnamed fiery orator blasts into the microphone in Pashto language with Arabic-language jihadist ballads playing in the background.
Voice of the Caliphate, the formal name of the IS radio station, can be heard in Jalalabad, the teeming capital of Afghanistan's eastern Nangarhar Province. Its broadcasts on 90 FM frequency can be heard across Nangarhar's 22 mountainous districts.
The hard-line jihadist group that now controls large parts of Syria and Iraq seems to be using its new Afghan radio broadcasts to spread anti-government propaganda among Nangarhar's estimated 1.5 million residents and attract the youth among them to its cause.
Zabihullah Zamary, a lawmaker in Nangarhar, says Daesh, an Arabic term commonly used to refer to the group, is using the broadcasts to increase its influence in Nangarhar, where hundreds have died in insurgent attacks and the government offensive against IS after militants overran large parts of some rural, eastern districts of Nangarhar close to the Pakistani border.
"We are determined to prevent them from destabilizing the government and using these broadcasts to propagate Daesh's hateful message to attract new recruits to their cause," he told Radio Free Afghanistan.
Nangarhar's Information and Culture Department, the local branch of a government ministry responsible for regulating media, still doesn't know where the radio broadcasts are coming from.
"We don't know much about the [new] radio station, which [apparently] broadcasts from an insecure [rural] area," Aworang Samim, the department's head, told Tolo tv.
Firdous Hazrati, the owner of Safa Radio, a commercial station in Nangarhar, says the IS radio has virtually overtaken their FM frequency 89.7 in many rural districts.
"I am calling on the government to take urgent steps to shut down this station soon," he told Radio Free Afghanistan.
Provincial government spokesman Attaullah Khogyani said authorities are unable to shut down the station because it broadcasts from across Nangarhar's eastern border with Pakistan.
He said the government has asked the Pakistani diplomatic mission in Jalalabad to help in shutting down the station. Islamabad, however, has not commented on the issue.
"[During the past few months,] Daesh's military strength has been downgraded. This is why they are now ramping up their propaganda campaign," Khogyani told Radio Free Afghanistan. "They are now using Facebook, other social media platforms, and radio broadcasts to magnify the effects of their propaganda."
IS first emerged in the region in January, when the militant group announced it had appointed a former Taliban commander, Hafiz Saeed Khan, as its leader for Afghanistan and Pakistan.
The organization, which described itself as the Khorasan Vilayat or Khorasan region, soon lost some of its key leaders in southern Afghanistan. By summer, Taliban militants and government attacks had crushed the IS affiliates in the southern provinces of Helmand and Farah.
But despite large-scale military operations, the group still retains influence in Nangarhar. General John Campbell, the U.S. commander of international forces, now sees a growing number of Afghan militants being attracted to IS.
Campbell told the Associated Press on December 15 that IS fighters were trying to establish a regional base in Jalalabad and "foreign fighters" from Syria and Iraq were joining them.
Afghanistan's fighting season usually ends after winter snows cover the Hindu Kush Mountains. IS now seems to be plotting to make a dramatic battlefield return in the new year.