BERLIN (Reuters) - A surge in violent attacks linked to Islamist groups in West Africa’s Sahel region reflects their growing capabilities and networking abilities, according to an international security conference report.

Three-quarters of battles with state security forces during 2018 were initiated by the groups, it said, according to extracts from the report, prepared for the annual Munich Security Conference and seen by Reuters on Friday.

It cited African Center for Strategic Studies data showing fatalities linked to Islamist militant activity more than doubled from 2017 to 1,082.

There was also a growing “security traffic jam” of military forces in the area including a United Nations mission, France’s Operation Barkhane, four European Union military and police training missions, and the G5 regional partnership established in 2015.

Security challenges include the area’s vast size, human trafficking, climate change and rapid population growth, the report said.

The violence in the Sahel region, a semi-arid band below the Sahara, has also alarmed Germany and the United States, who have sent thousands of troops there to counter al Qaeda and Islamic State-linked groups.

The report is due to be published on Monday. The Conference will bring together more than 600 government leaders and other decision makers from Feb. 15-17.