An elderly Jesuit priest who was described as “beloved” and “a symbol of suffering and compassion” was shot dead Monday at his monastery by a masked gunman in Syria, an attack that is being condemned by Syrians, the U.S. government and the United Nations.

The killing of Father Francis Van Der Lugt, who was originally from the Netherlands, has further stoked fear among Syria’s embattled Christian community for their future in the country where hardline rebels are trying to oust President Bashar Assad and institute Islamic law.

That Associated Press reported that the 75-year-old clergyman had lived in Syria for almost 50 years, spoke Arabic, and “refused to leave Homs even as hundreds of civilians were evacuated from rebel-held districts of Homs that have been besieged for more than a year by Assad’s forces.”

In this photo taken on March 28, 2014 and released by a neutral activist youth group, About our Neighborhood Hamidiyeh Simply, which has been authenticated based on its contents and other AP reporting, shows Dutch Father Francis Van Der Lugt, 75, in Homs, Syria. A masked gunman opened fire on Van Der Lugt, a well-known elderly Dutch priest, in the central Syrian city of Homs on Monday, killing him instantly, a fellow priest and an activist group said. (AP Photo/About our Neighborhood Hamidiyeh Simply)

In this photo taken on March 28, 2014 and released by a neutral activist youth group, About our Neighborhood Hamidiyeh Simply, which has been authenticated based on its contents and other AP reporting, shows Dutch Father Francis Van Der Lugt, 75, in Homs, Syria. A masked gunman opened fire on Van Der Lugt, a well-known elderly Dutch priest, in the central Syrian city of Homs on Monday, killing him instantly, a fellow priest and an activist group said. (AP Photo/About our Neighborhood Hamidiyeh Simply)

Witnesses said the gunman entered the monastery and took Van Der Lugt to the garden where he shot the clergy member. The Jesuit order in the Netherlands said the priest was shot twice in the head.

Reuters quoted an interview by Vatican Radio with Rev. Ziad Hillal, another Jesuit who lived at the monastery with the Dutch priest, who said, “Father Frans was killed in the garden of our monastery.”

“They shot him in the head. It was a premeditated act,” Hillal added.

Vatican spokesman the Rev. Federico Lombardi called Van Der Lugt a man of great courage who “despite an extremely difficult and risky situation, wanted to remain faithful to the Syrian people to whom he had dedicated his life and his spiritual service.”

“The death of the priest is a scandal for the rebels,” an antigovernment activist Mahmoud Taha told the New York Times. “They no longer accept anyone but those who are like them.”

State Department spokeswoman Jen Psaki said the U.S. was “saddened by the news” of the priest’s killing.

“We condemn this violent attack and all attacks against innocent civilians and minority communities,” Psaki said. “As we have said throughout this conflict, we deplore continued threats against Christians in Syria, and we reiterate that we stand on the side of the Syrian people, who are fighting for a Syria that is inclusive and pluralistic and respects all faiths.”

U.N. Secretary-General Ban Ki-moon condemned the killing as an “inhumane act of violence.”

Van Der Lugt was well-known in Homs, a city held by rebels and blockaded by the government. The priest was commended for his efforts to lift the siege so that aid could be transported into the city. His friends told the Associated Press that he had repeatedly refused to evacuate the city until all Christians could leave.

Beibars Tilawi, a local activist, told the AP, “The man was living with us, eating with us, sleeping with us. He didn’t leave, even when the blockade was eased.”

Albert Abdul-Massih, who worked with Van Der Lugt, told Reuters that the slain priest had a PhD in psychiatry and lived an austere life.

“We learned humanity from him, and he used to love Muslims as much as he loves Christians,” Abdul-Massih said. “He was treating people for free and he was a fluent Arabic speaker.”

No group or individual claimed responsibility for his killing and no motives were reported.

The Al Qaeda-linked Nusra Front has gained more influence among rebels in the central city of Homs and elsewhere in Syria.

In an interview in February to ReliefWeb which covers humanitarian organizations, Van Der Lugt said, “I don’t see Muslims or Christians, I see, above all, human beings.”

Those individuals “hunger to lead a normal life,” he said according to the New York Times.  As the only priest left in the Old City to help others, he said, “How can I leave? This is impossible.”

According to the AP, another Jesuit priest in Syria, Father Paolo Dall’Oglio of Italy, has been missing since July after traveling to meet Islamic militants. Two Greek Orthodox bishops are still missing since being grabbed from their car by gunmen outside Aleppo.