Beirut (dpa) - Islamic State has abducted around 900 mainly Kurd civilians in northern Syria over the past three weeks as Kurdish-led insurgents attempt to dislodge the extremists from their strongholds in the area, a monitoring group said Friday.
The kidnappings took place in villages near the Islamic State-controlled town of al-Bab in the province north-east of Aleppo, the Syrian Observatory for Human Rights added.
"The 900 included some Arabs from the villages near al-Bab, but the majority are Kurds," Observatory head Rami Abdel-Rahman told dpa.
The militants transferred some 350 of the people abducted to al-Raqqa, the de facto capital of Islamic State in Syria, he said.
The others were reportedly taken to detention centres inside Islamic State-held areas in northern Syria.
The extremists executed 13 civilians and shot dead five more who attempted to escape, the Observatory said.
On May 31, the Kurd-led Democratic Forces of Syria (DFS) started an offensive to drive Islamic State from the northern town of Minbij, which is less than 20 kilometres from the Turkish border.
The DFS, a US-backed alliance of Arabs and Kurds, entered Minbij on Thursday.
Minbij, under Islamic State's rule since 2014, is strategically important because of its location along a supply route from the Turkish border to al-Raqqa.
Meanwhile, DFS forces made more important strategic advances towards the centre of the city of Minbij, Abdel Rahman said.
"The DFS made a crucial and important advances towards Swamaa and Dowar al-Matahin, which is only two kilometres from the center of the city of Minbij," he said, adding that half of the city of Minbij is now "under the DFS's direct fire."
On Thursday, the DFS backed by US airstrikes, stormed the town from the south-west.