Philippine communist leader Jose Maria Sison died on Friday night at the age of 83 after a two-week confinement in a hospital in the Netherlands, his party said on Saturday.
Sison is the founder of the Philippine Communist Party, whose military wing -- the New People's Army (NPA) -- has been waging an armed rebellion in one of the world's longest-running insurgencies.
The conflict between the NPA and the Philippine government has killed more than 40,000 people.
"The Filipino proletariat and toiling people grieve the death of their teacher and guiding light," the party said in a statement on its website.
The self-exiled communist leader has lived in Europe since the late 1980s, after his release from jail following the fall of dictator Ferdinand Marcos, whose namesake son was elected president in a May election this year.
Sison was put on a US terrorist list in 2002, preventing him from traveling.
The party said Sison died peacefully at around 8:40 p.m. local time on Friday after being confined in the hospital in Utrecht. It did not give a reason for Sison's confinement.
"Even as we mourn, we vow (to) continue to give all our strength and determination to carry the revolution forward guided by the memory and teachings of the people's beloved Ka Joma," the party said.
Sison was also known as Joma and "Ka" means comrade.
President Marcos' predecessor, Rodrigo Duterte, had prioritized ending the conflict when he took office in 2016, but he abandoned peace efforts, infuriated by repeated rebel attacks during the talks
At its peak, the NPA had 25,000 armed fighters, but now has about 2,000, the military has said.