Ground fighting alone has killed more than 600 combatants since Islamic State group jihadists launched an offensive on the Syrian Kurdish enclave of Kobane a month ago, a monitoring group said Thursday.

The Syrian Observatory for Human Rights said its toll did not include the “several hundred” IS fighters that the Pentagon says have been killed in US-led air strikes in and around Kobane.

Thick smoke in Kobane’s city centre

Between September 16 and midnight (2100 GMT) on Wednesday a total of 662 people were killed in ground fighting, said the Britain-based monitoring group, which has a wide network of sources inside Syria.

They included 20 civilians, Observatory director Rami Abdel Rahman told AFP.

IS lost 374 of its militants, while 268 people have been killed fighting on the Kurdish side, he said.