Russia Foreign Ministry has asked Afghan, U.S. and NATO officials to provide a “rational explanation” about reports of unidentified helicopters providing support to ISIS-K militants in Afghanistan.

“We’ve taken note of new reports about unmarked helicopters ferrying the fighters of ISIS Afghan branch, as well as weapons and munitions for them, in eastern Afghanistan,” Russia Foreign Ministry spokesperson Maria Zakharova told reporters during a press briefing on Wednesday.

Zakharova also pointed to the brief capture of Tora Bora, a strategic cave in Pachiragam district of Nangarhar, by IS fighters on June 14 which was recaptured by Afghan security forces during a clearing operation.

“Some reports say that shortly before this, unmarked helicopters delivered over 50 armed extremists to reinforce the fighters who were preparing an offensive on Tora Bora, as well as a container full of weapons and munitions,” she added.

IS militants also known as Daesh is widely active in some parts of Nangarhar province and there were reports of the group activities in some other provinces of the country as well.

“It is symptomatic that neither the Afghan authorities nor the U.S. and NATO military contingent officials in Afghanistan have offered a rational explanation for the increased number of flights made by unidentified helicopters providing support to ISIS fighters in many Afghan provinces, Zakharova stated,” Silence in this case is becoming increasingly conspicuous.”

She further asked Western media to ask these questions from the Pentagon, the White House and the U.S. State Department.

Immediately there was no reaction from U.S. officials regarding the statements made by Moscow while Afghan ministry of defense have rejected the report and called it baseless.

Afghan and U.S. forces have conducted many counter terrorism operations against the IS fighters in Nangarhar province during the last two years.

Reports of unidentified helicopters landing in Taliban controlled areas in Sar-e-Pul and Ghazni districts of Afghanistan have also been published during the last couple of months.

In a latest report by an official U.S. watchdog, U.S. officials have expressed concerns about the security situation in Afghanistan as Russia, Pakistan and Iran are providing support to the insurgents fighting the Kabul government.