Local officials and independent analysts have said some 5,000 foreign insurgents, including much of their leadership, are currently residing in northern Afghanistan. The militants, moved recently from Kunar and Nuristan provinces, have been blamed for the spike in violence seen in a number of provinces in recent weeks.

Local officials reported the presence of leadership elements for foreign insurgents from Uzbekistan, Chechnya, the Arabian Peninsula, Turkmenistan and China's Uighur community.

While security officials from the ministries of defense and interior confirmed that foreign fighters are largely behind much of the recent turbulence in traditionally less restive parts of the country, they said there remains no conclusive intelligence regarding their numbers.

Nevertheless, Jawed Kohistani, a political analyst who spoke with TOLOnews, spoke freely about the estimated size and suspected origin of the foreign militants. "Approximately, there are between 4,000 to 5,000 foreign fighters who live with their families in the border areas, from Durand to the North," Kohistani said on Tuesday. "Most of these families, which are supported by Pakistan and Saudi Arabia, are familiar with warfare," he added.

Based on reports by local officials, Faryab, Sar-e Pul, Kunduz, Badakhshan, parts of Takhar, Maidan Wardak and Jowzjan are the northern and north eastern provinces where the largest foreign fighter contingents are said to be based with their families. The insurgent influx has been attributed to a militant pipeline from Northern Waziristan to Kunar and Nuristan provinces, and into Afghanistan's north through the borders of Zabul and Ghazni.

Still, the Ministry of Interior (MoI) resisted sharing details when asked about the possible location and origin of the foreign fighters. "We found out from people that foreign fighters are present in northern provinces, but investigative work is ongoing regarding the location and how the foreign fighters came to these areas," ministry spokesman Sediq Seddiqqi said.

The surge in militant activity in recent months has not been isolated to the north, with fighting raging between the Afghan National Security Forces (ANSF) and anti-government militants in Helmand, Ghazni, Zabul, Maidan Wardak in the south and Farah and Badghis in the west. Security officials have reported clashing primarily with foreign fighters and not Afghan Taliban.

According to some local reports, the families of the foreign insurgents have been involved in the fighting, propaganda and explosives preparation.

While the governor of Ghazni has gone so far as to claim 150,000 insurgents have moved from Pakistan with their families to a few districts of this province, specifically Nawa and Nahwar, the Ministry of Defense (MoD) has denied the reported figures and refrained from presenting alternative intelligence.

"No one can deny that the battles are against foreign insurgents, but it is not the number that has been said," MoD deputy spokesman Dawlat Waziri told TOLOnews.

One rationale analysts provided for the mass militant migration was the Pakistani military's offensive in North Waziristan and other places along the tribal belt in 2014.