MANILA, Philippines — The armed wing of the Communist Party of the Philippines (CPP), the New People’s Army (NPA), is identified in an international study as the “largest individual group” suspected to be behind terrorist incidents in the Philippines last year.

The Global Terrorism Index 2014 released Tuesday by Sydney-based think tank Institute for Economics and Peace noted that the NPA claimed responsibility for 30 percent of deaths from terrorist-related incidents in 2013.

“Whilst there were seven known groups that carried out a terrorist act in 2013, most activity is carried out by the New People’s Army, Moro Islamic Liberation Front and the Abu Sayyaf Group,” it noted.

Incidents deemed to be terrorist acts in the Philippines in 2013. GTI 2014/Institute for Economics and Peace

The CPP-NPA was designated a foreign terrorist organization by the United States State Department in 2002.

The study, which ranks the Philippines ninth of 162 countries in the terrorism index, identified 499 incidents that caused 292 deaths and 444 injuries the past year.

READ: Philippines 9th of 162 countries in terrorism index

Incidents counted in the study are those deemed to be of “an intentional act of violence or threat of violence by a non-state sector” or sub-national actors aiming to attain political, economic, religious or social goal.

“Armed assault represented nearly half of all fatalities, followed by assassinations, which constituted a quarter of all fatalities,” the researchers wrote.

The acts differ from the worldwide terrorist trend of using explosives.

In the Philippines, 56 percent of assassination attempts were successful, killing 103 people. The number is “more than five times higher than 2012.”

“The use of these tactics and targets demonstrates that many of the terrorist groups in the Philippines are seeking to directly change the political system,” the study said.

The Abu Sayyaf, meanwhile, was the only group engaged in suicide bombing.

Around 34 percent of deaths from terrorist attacks were believed to be targeting government or troops, while only 10 to 17 percent of deaths are of business leaders, private citizens and police.

Based on information since the 1960s, terrorist groups are permanently ended when they either join the political process, become a state-recognized political party or stopped by policing and intelligence agencies that break them up.

“Military force in of itself was rarely responsible for ending terrorist groups,” the study said.