Plans are being drawn up online via a Telegram channel, set up six days ago and followed by almost 70,000 people. Organisers are calling on people to bring sleeping bags, tents, life jackets, water, canned food and first aid kits.

"We will announce it when it's time to go," one organiser, a 46-year-old refugee who wished to remain anonymous, told AFP.

Some of the organisers already lived in the EU, he added.

Organisers say the caravan will be split into groups of up to 50 people, each led by a supervisor.

"We have been in Turkey for 10 years," read one message posted on the channel by an administrator. "We are protected... but Western countries must share the burden."

There are 3.7 million Syrian refugees officially living in Turkey.

Syria's civil war, which began with a brutal crackdown of anti-government protests in 2011, has killed nearly half a million people and forced around half of the country's pre-war population from their homes.

Many Syrian refugees in Turkey fear being sent back, especially after a recent shift in Turkey's stance towards Damascus.

Turkish President Recep Tayyip Erdogan has said he is preparing to send back one million Syrian refugees on a voluntary basis.

In February and March 2020, tens of thousands of migrants approached the land border between Turkey and Greece, after Erdogan threatened to keep the borders with Europe open.