For every Syrian refugee returned, another Syrian refugee will be resettled from Turkey to the EU, with numbers capped at 72,000.

Buses believed to be carrying hundreds of migrants for deportation to Turkey arrived at the Greek island ports of Lesbos and Chios early Monday morning, Agence France-Presse reporters said.

By midday, a ferry reportedly arrived in the Turkish port of Dikili on Monday carrying the first migrants sent back by Greece under a EU-Turkish deal aimed at curbing Europe’s migration crisis, AFP reporters saw.

The catamaran Nezli Jale arrived from the Greek island of Lesbos at 9:20am (0620 GMT) with several dozen passengers on board. Several hundred migrants are expected to arrive Monday in Dikili and the port of Cesme on the first day of operations.

The expulsion launches a controversial EU deal to send migrants back across the Aegean Sea that has been criticized by rights groups on ethical grounds.

On Lesbos, crews were earlier seen loading supplies onto the ships — a small ferry and a catamaran.

Turkish Interior Minister Efkan Ala has said his country is ready to receive 500 migrants on Monday and Greek authorities have provided 400 names, although these numbers could change.

The European Union signed the controversial deal with Turkey in March as it wrestles with the continent’s worst migration crisis since World War II, with more than a million people arriving last year.

Under the agreement, designed to halt new arrivals along the most popular route through Turkey, all “irregular migrants” arriving since March 20 face being sent back. Each case is meant to be examined individually.

For every Syrian refugee returned, another Syrian refugee will be resettled from Turkey to the EU, with numbers capped at 72,000.

A Turkish-flagged passenger boat carrying migrants to be returned to Turkey leaves the port of Mytilene on the Greek island of Lesbos.

Activists hold placards as they protest against the return of migrants to Turkey, at the port of Mytilene on the Greek island of Lesbos.

Related articles across the web

• When will Cameron realise he can't win the EU referendum by scaring us?
• EU/SPC give thousands of seedlings to Fiji
• Mali hotel attack: Gunmen 'storm EU military training base in Bamako'
• TTIP "Trade" Regime Would Let EU Meddle in U.S. Policy
• Should Britain Remain in the European Union?
• In wake of Brussels attacks, Europe demands negotiated Settlement of Syrian Civil War, Now
• Will the EU dissemble amid security threats? [CARTOON]
• Refugee sets himself alight as EU's grand plan to staunch exodus of asylum seekers unravels
• EU Vows to Deepen Intel Sharing Following Brussels Attacks
• [Ticker] Oxfam withdraws from Lesbos in protest