More than 170 have been killed, including Christians, in fighting between the Filipino government and extremist militants that have allied themselves with the Islamic State (IS) in a majority-Muslim island in the Philippines, since May 23, according to reports.

Instability and violence in the island of Mindanao, and particularly the city of Marawi, began when the extremist group, known as the Maute group, tried to capture a militant leader in the Philippines who is affiliated with the Islamic State, according to BBC News. Violence ensued when the Maute group’s attempt failed, and the group has been taking hostages, freeing prisoners, and carrying out attacks since.

In late May, the Maute group, which itself has also pledged allegiance to ISIS, is reported to have taken dozens of hostages from a church, and on May 23, eight Christians were shot and killed for refusing to recite the ‘shahada,’ the creed of the Islamic faith, according to Morning Star News.

A video that was released on May 30 showed that the Maute group kidnapped a Catholic vicar-general, Rev. Teresito “Chito” Suganob, who appeared in the video pleading the government to stop bombing the city. Reports say that 13 other members of the St. Mary’s Cathedral were kidnapped along with Suganob.

“Mr. President [Rodrigo Duterte], we are in the midst of this war … We are asking for your help to please give what they are asking for, to withdraw forces away from Lanao del Sur and Marawi City, and to stop the air attacks, and to stop the cannons,” Suganob was quoted as saying in the video by Morning Star News.

Since May 23, Duterte began enforcing martial law in the island of Mindanao.

Sidney Jones, director of the Institute for Policy Analysis of Conflict in Jakarta, Indonesia, wrote in a New York Times op-ed that the government must become more strategic in fighting the growing extremist militancy in Mindanao.

“The Duterte administration’s response to Islamist extremism so far has been to try to crush it militarily,” Jones wrote. “But too often strong-arm tactics only breed more fighters — and fighters with a desire for revenge. The Philippine government must instead come up with a comprehensive strategy to fix the social, economic and political problems that have led Islamic State ideologues to exert so much appeal in Mindanao.”

“We are very concerned about the lives of hostages (among them a priest and 15 Catholics …) since we do not know what their fate may be,” Edwin de la Pena, the Bishop of Marawi, told Fides Catholic news agency in an early June report.

“Now there are ongoing contacts and militants threaten to decapitate Fr. Chito. The hostages are their guarantee of survival. We hope that the militants decide to release them safe and sound,” he said.

According to reports, hundreds of thousands have fled the island since the violence broke out. However, BBC News reported on June 4 that some 2,000 are estimated to still be trapped in the city.