Greeks and Turks are waging a proxy war on social media with photos, video and commentary purporting to show the other side behaving badly in a migrant crisis that has seriously strained already tense relations between Athens and Ankara.

An estimated 35,000 migrants from the Middle East, Afghanistan, Pakistan and elsewhere have been trying to enter Greece, a European Union member state, since Ankara said on Feb. 28 it would no longer keep migrants on its territory as required under a 2016 deal with the European Union in return for aid.

Greece has used tear gas and water cannon to hold them back.

On Greek Twitter, the hashtags GreeceUnderAttack and GreeceDefendsEurope have become common. On Turkish Twitter KahpeYunan (GreekBitch) was briefly a trending topic. Foreign Minister Mevlut Cavusoglu used the tag GreeceAttacksRefugees.

One video circulating on Monday appeared to show a tractor on the Greek side spraying liquid toward the border fence, dousing hundreds of migrants gathered on the Turkish side.

Some Greek social media users speculated it was a farmer spraying pig urine along the border. Turkish social media users said it showed Greek police and farmers spraying chemical weapons and tagged the United Nations.

Read more: Reuters