THESSALONIKI, Greece (AP) — Clashes broke out overnight on Greece's border with Turkey early Wednesday, after 500 migrants attempted to break down a border fence and enter Greece.

Greek police said they used tear gas to repel the push to break down the fence south of the Kastanies border crossing. They said Turkish authorities also fired tear gas at the Greek border. The clashes began at 2 a.m. and lasted for roughly two hours.

An estimated 2,000 migrants are still camped out on the Greek-Turkish border, weeks after Turkey declared its borders to Europe open and encouraged migrants and refugees living in the country to try crossing into European Union member Greece.

Tens of thousands of people headed to the border despite Greece’s insistence that its eastern border, which is also the EU’s external border, was shut. The move came after months of threats by Turkish President Recep Tayyip Erdogan that he would open his borders and allow millions of refugees into Europe unless the EU provided more support for refugee care in Turkey.

The EU says it is adhering to a 2016 deal with Turkey under which it provides billions of euros in funds in return for Turkey caring for more than 3.5 million refugees from neighboring Syria.