Substantial territorial losses have driven Islamic State (ISIS/ISIL) jihadists to carry out an unprecedented number of attacks in the first three months of 2016, particularly in their Syrian and Iraqi strongholds, according to a news analysis by IHS Jane’s Terrorism and Insurgency Center (JTIC).

Islamic State carried out 891 attacks in Iraq and Syria during the first quarter of 2016, more than at any point since the terrorist group first rose to power when it conquered Mosul in June 2014, revealed the new IHS report.

An estimated 2,150 people died as a result of those attacks, marking a 44 percent increase over the previous quarter and the highest quarterly death toll in nearly a year.

“Following territorial losses, we are seeing a steady upward trend in the tempo of Islamic State operations worldwide, but particularly in Syria and Iraq,” said Matthew Henman, head of IHS Jane’s Terrorism and Insurgency Centre (JTIC), in a press release issued Monday. “Attack and fatality numbers have jumped. The group is resorting more and more to mass-casualty violence as it comes under heavy pressure from multiple angles.”

The IHS report highlighted an increase in ISIS attacks in Libya, where the U.S. military estimates the number of jihadists fighting on behalf of the terrorist group has more than doubled to between 4,000 and 6,000 in the last 12 to 18 months.

“Islamic State attacks are intensifying in Libya after a several month slump,” Henman said.

He later added:

After a seeming period of consolidation and preparation, Islamic State forces in the country launched a series of major attacks on critical energy infrastructure in addition to conducting the deadliest single attack since the overthrow of the government of Muammar Ghadaffi in August 2011.

Without providing specific figures, IHS pointed out in its press release that the number of attacks in Libya during the first quarter of 2016 were nearly equivalent the those that occurred during the third and fourth quarters of 2015 combined.

U.S. defense officials estimate that ISIS has lost 30 percent of the territory it once held in Iraq (40 percent) and Syria (20 percent).

Moreover, the U.S. military reports that the number of foreign fighters traveling into Iraq and Syria to join ISIS has dropped by 90 percent within the past year to nearly 200 per month, signaling a decrease in the group’s strength.

Backed by U.S.-led coalition airstrikes, Iraqi forces retook Ramadi late last year and are preparing to launch an offensive to rout the ISIS jihadists from the northern city of Mosul.

Bashar al-Assad troops in Syria, bolstered by Russian air power, have recaptured territory from ISIS, including the ancient city of Palmyra.

Kurdish fighters, supported by U.S-led coalition airstrikes, are also putting pressure on the jihadist group in north and northeastern Syria.