Thousands of foreign fighters in about 100 countries are fighting for Al-Qaeda and Daesh groups, according to a UN report.

The UN experts have told the UN Security Council that 6,500 foreign militants fighting in Afghanistan have links to Al-Qaeda and Daesh extremists.

‎According to the experts, Iraq and Syria, where more than 22,000 foreign fighters are engaged in fighting, are comprising a "veritable international finishing school for extremists."

Hundreds more foreign fighters were fighting in Libya, Yemen, Somalia and Pakistan, the report added.

‎The UN report came a day after a group of Uzbek militants claiming to be the members of Islamic Movement of Uzbekistan (IMU) militant group allegedly sworn allegiance to Daesh extremists in Afghanistan.

They have released a video purportedly showing the beheading of an Afghan soldier in retaliation to detention of a number of female IMU supporters by the Afghan security forces in northern Faryab.

The Afghan government officials, however, are yet to comment about IMU allegiance to Daesh and the new UN report.