A car bomb killed at least 13 people in a Turkish-held border town in northeast Syria Saturday, as thousands of Kurds in the wider region protested against a "Turkish occupation".

The bombing ripped through Tal Abyad, one of several once Kurdish-controlled towns seized by Turkey last month in a deadly cross-border offensive.

The blast came despite a truce last week to halt a Turkish assault that began on October 9 and sparked the latest humanitarian disaster of Syria's eight-year civil war.

On Saturday, an AFP correspondent in Tal Abyad saw the skeletons of two motorbikes ablaze in the middle of a rubble-strewn street.

A group of men carried the severely burnt body of a victim onto the back of a pickup truck, as a veiled young woman stood aghast by the side of the street.

Turkey's defence ministry said 13 civilians were killed in the attack, which it blamed on Kurdish fighters. The Syrian Observatory for Human Rights, a Britain-based war monitor, reported 14 people - pro-Ankara fighters and civilians - had been killed in the explosion.

Meanwhile, in the Kurdish-majority city of Qamishli, thousands of Syrian Kurds marched in the streets to protest what they view as a Turkish invasion.

"No to Turkish occupation," they cried, brandishing flags of their once semi-autonomous region and its fighters.