Greek authorities say they have started resettling migrants living in tents in a park in the capital Athens, but many are wary and have moved out ahead of the operation.

Fire brigade buses have begun moving migrants, most of them from Afghanistan, to a settlement of 90 containers in the Athens district of Votanikos. Each container can house six to eight people and has air conditioning, running water and a toilet.

The government has said the place is not a detention center and that everyone is free to come and go. However, many migrants, wary of such promises, packed their belongings and left the park.

More than 130,000 migrants have reached Greece so far in 2015, straining the country's resources.