A senior church leader in Syria has condemned Turkey’s new military offensive as “unjustified aggression” and urged the international community to exert “maximum pressure” to prevent a humanitarian catastrophe.

Rev. Abdalla Homsi, of the Evangelical Christian Alliance Church of Aleppo, issued a statement as an estimated 5,000 people were reported to have fled their homes in the Afrin region on the border with Turkey.

Turkey is trying to oust from the region Kurdish People’s Protection Units (YPG) that it considers a terrorist group. The US is reportedly helping the units form a 30,000-strong “border security force”.

Rev. Homsi said: “We condemn the unjustified Turkish aggression against our Syrian citizens from the Kurdish background, who were safely and peacefully living in Afrin.

“We plea all humanitarian and international organisations to exercise maximum pressure to stop this criminal act.

“This brutal bombardment and assault of the civilian population will inevitably lead to a tragedy, a new humanitarian catastrophe, and a wave of displacement and suffering that will deepen the wounds of our wounded Syrian homeland.”

The UN said in a statement yesterday that it could deliver aid to 50,000 people in Afrin if needed. It noted that local authorities in Afrin had closed exit points, preventing civilians from reaching safer locations nearby.

The UK-based Syrian Observatory for Human Rights reports that at least 27 civilians have been killed, including four women and eight children, as well as 25 Syrian rebels and 26 Kurdish fighters. Turkey denies killing civilians.

Watching developments in Afrin closely. Turkey is right to want to keep its borders secure. We share goal of reducing violence and keeping focus on most important task: a political process in Syria that leads to the end of the Asad regime. — Boris Johnson (@BorisJohnson) January 22, 2018

The monitoring body also noted that the Turkish forces are fighting alongside “rebel and Islamic factions”.

On Sunday (21 January) another church in Afrin issued a plea for protection from the international community after the area came under fire from Turkish ground and air troops.

Pastor Valentin Hnan of the church of the Good Shepherd in Afrin, north-western Syria, wrote in an email to his supporters: “We are at this moment under heavy shelling, and Islamic groups are threatening to enter the area.”

Over 200 families attend the Good Shepherd church, and Kurdish-majority Afrin has welcomed thousands of Syrians trying to cross the border into Turkey to flee civil war.

In Damascus a senior church leader urged the international community to stop supporting irregular militias operating in Syrian territory. The Vatican-linked news agency Fides reported that the Syriac Orthodox Patriarch of Antioch, Mar Ignatius Aphrem II, told a gathering of diplomats “to put an end to all forms of external support for irregular militias and armed groups operating in Syrian territory”. The reception was attended by Syria’s deputy foreign minister Faisal Mekdad and Vatican envoy Cardinal Mario Zenari.

A number of villages in the region have been captured by Turkish forces, according to Turkish media.

Fighting alongside members of the coalition-backed Free Syrian Army, the Turkish military aims to create a 30km “safe zone” within Syria to protect its border.

“We are determined, Afrin will be sorted out,” Turkish President Recep Tayyip Erdoğan said in a live television broadcast in Ankara on Monday (22 January).

Turkey’s military might was trained on Afrin because of the local population’s strong support for imprisoned Kurdistan Workers Party leader Abdullah Ocalan, Al-Monitor reported.

The UK’s foreign minister, Boris Johnson, said of his country’s Nato ally: “Turkey is right to want to keep its borders secure”.