"We have decided to immediately extend the fence in three different areas," the government source told AFP, adding that the new sections, to the south of the area now under pressure, would cover around 36 kilometres (22 miles).

The current stretch of fence will also be upgraded, the official added.

Tens of thousands of asylum-seekers have been trying to break through the land border from Turkey for a week after Ankara announced it would no longer prevent people from trying to cross into the European Union.

A police source Sunday told AFP that riot police reinforcements from around the country had been sent to the border in recent days, in addition to drones and police dogs.

There have been numerous exchanges of tear gas and stones between Greek riot police and migrants.

Copyright Agence France-Presse, 2020