New Delhi, July 31 -- The threat from Islamic State and al-Qaida extremists and their affiliates is most intense in parts of Africa, and risks are growing in Syria, which both groups view as a "a strategic base for external operations," U.N. experts said in a new report.

Their report to the U.N. Security Council circulated Wednesday said West Africa's al-Qaida-linked Jama'at Nasr al-Islam wal-Muslimin group, known as JNIM, and East Africa's al-Qaida-linked al-Shabab have continued to increase the territory under their control.

The experts monitoring sanctions against the two groups said "the organization's pivot towards parts of Africa continued" partly because of Islamic State losses in the Middle East due to counterterrorism pressures...