Four police assaulted at pro-Kurd rally in Berlin

Four police officers were assaulted and three people arrested at a pro-Kurd protest in Berlin on Saturday, while demonstrating against Turkey's military offensive in Syria.

Thousands of people marched amid a heavy police presence under the banner "Together against Turkish attacks in Afrin", referring to the region in northern Syria where Turkey is waging a campaign against a Syrian Kurd militia.

Organisers, including NGO's, Kurdish groups and some political parties, said 30,000 people took part, but police estimated "several thousand" and said overall the march passed "without disorder".

Ankara launched the offensive in January against the Syrian Kurdish People's Protection Units (YPG), which is allied with US forces against the Islamic State (IS) group.

Ankara views the YPG as a terror group, and the Syrian branch of the Kurdistan Workers' Party (PKK).

The PKK, which is banned in Turkey and is considered a terror group by the US and European Union, has waged an insurgency against the Turkish state for more than three decades.

The protest came as Turkish airstrikes in Afrin killed at least 36 pro-regime troops on Saturday, according the Syrian Observatory for Human Rights (SOHR).

The strikes resulted in extensive material damage of the base as well as scores of casualties, and is the third such strike by Turkey against Assad's forces in the border enclave in 48 hours, according to SOHR.

At least 22 casualties of Syrian regime forces had previously been counted, since the Syrian army entered Afrin as part of an agreement to support the besieged Kurdish forces who previously controlled the area.