The Taliban victory in Afghanistan has raised concern in Turkey, a staging post for many migrants trying to reach Europe and already home to nearly 4 million Syrians, of a new influx of refugees. It has ramped up security on its border with Iran - but some Afghans are still getting through.

Sheltering in a drainage tunnel outside the Tatvan district of Turkey's eastern Bitlis province, Ali, a young man in his 20s from Afghanistan's Khost province, said he was waiting for transport west and wanted to go on to Europe. Around 50 others were sheltering with him.

Ali said he had studied computer science and taught web and graphic design in Afghanistan. He said he had a YouTube channel where he posted videos on topics including how to make money online.

"I was planning a bitcoin or ethereum mining business... Suddenly everything changed and the Taliban took over all of Afghanistan," he said.