UNITED NATIONS (AP) — A top U.N. counterterrorism official told the Security Council on Thursday that a vast stretch of Africa could fall under the control of the Islamic State group and affiliated terrorist organizations.

There was no known link between an alleged plot to attack Taylor Swift shows in Vienna and the group or its affiliates elsewhere in the world, but both suspects appeared to be inspired by the Islamic State group and al-Qaida, Austrian authorities said Thursday.

In a regular report to the council, Vladimir Voronkov, the undersecretary for counterterrorism, told members that IS group affiliates have “expanded and consolidated their area of operations” in West Africa and the Sahel.

A “vast territory stretching from Mali to northern Nigeria could fall under their effective control” if their influence continues, Voronkov said.

He said that IS group affiliates have also expanded operations in other parts of the continent, including parts of Mozambique, Somalia, and the Democratic Republic of the Congo, which saw a “dramatic increase in terrorist attacks” that killed large numbers of civilians.

Voronkov told the council that ISIS-K, the group’s Afghanistan affiliate, has “improved its financial and logistical capabilities” in the last six months and increased recruitment efforts. He said IS has demonstrated its global intent by claiming responsibility for ISIS-K attacks and increasing operations in Iraq and Syria.