Kurdish separatist fighters have claimed responsibility for sabotaging a pipeline that travels through Turkey, helping push global oil prices back above $120 a barrel.

The Baku-Tbilisi-Ceyhan pipeline, which brings Azeri oil from the Caspian Sea to the Mediterranean for westbound shipments, caught fire on Tuesday night.

According to local news reports, the pipeline could remain shut down for up to 15 days.

It is not clear what started the blaze and by late Thursday, the fire still had not been fully extinguished.

The claim of responsibility by the Kurdistan Workers' Party (PKK) was reported by the pro-Kurdish news agency Firat.