Bulgaria, Greece and Turkey agreed on Monday to set up a common border police and customs centre to exchange information to combat a surge in illegal migration.

"This agreement guarantees closer cooperation of the three countries that face one and the same challenges... migration, organised crime and terrorism," Bulgaria's Interior Minister Rumyana Bachvarova said after a signing ceremony in Sofia.

The centre will be set up at the Kapitan Andreevo border checkpoint between Bulgaria and Turkey, which also borders Greece, she added.

Turkey's Interior Minister Sebahattin Ozturk explained that the centre will allow "police and customs authorities to exchange information in real time and react to stop illegal migration and smuggling."

Turkey currently hosts about two million refugees, mostly from neighbouring conflict-torn Syria.
Thousands of those exiles attempt to illegally cross from Turkey into Bulgaria and Greece seeking refuge in the European Union, prompting both Sofia and Ankara to build protective fences to try and stop the flow.

The three countries have long discussed setting up joint police teams to patrol the frontier.

Bulgaria has stepped up security checks at its border checkpoints this year as the fence forced increasing numbers of migrants to cross hidden in trucks and trains.

Most refugees say they pay Turkish human traffickers to help them cross over, but on Monday Bulgarian police detained a border policeman from the Lesovo checkpoint who was trying to smuggle two Iraqis in his car.