There was no immediate claim of responsibility for the attack. Unconfirmed reports say gunfire was heard after the blast, which shattered the windows of nearby buildings.
Three Turkish soldiers were killed and 14 others wounded in a car bomb attack on Sunday in front of police headquarters in Turkey’s southeastern city of Gaziantep
Broadcaster Haberturk TV said the blast hit near a bus station in the city, the largest in the mainly Kurdish southeast. Ambulances rushed to the scene, Haberturk said.
The arrests come after a suicide bomber in Istanbul killed two American-Israelis, another Israeli and an Iranian.
The explosion hit Istiklal Street, a wide boulevard closed to traffic that is lined with international stores and shopping centres, just a few hundred metres from an area where police buses are usually parked, a Reuters witness said.
Turkish Prime Minister Ahmet Davutoglu, whose country is home to almost 3 million Syria refugees, proclaimed the agreement a momentous occasion.
Turkey has been wracked by conflict in mainly Kurdish areas of the southeast and suffered a string of attacks.
The Kurdistan Freedom Falcons is considered an offshoot of the PKK and has carried out several attacks in the past including one in Ankara in February.
For every irregular migrant returned to Turkey, EU countries would take in one Syrian refugee from Turkey, in a process supervised by the UNHCR.
The European Union and Turkey hope to reach a comprehensive deal this week to tackle illegal migration and the refugee crisis spurred by conflicts in Syria and beyond.
The military denied Moscow’s claim that Turkey’s military is entrenched a few hundred yards inside Syrian territory to prevent Kurdish groups from strengthening their positions.
Following the attack, Turkish warplanes bombed camps belonging to the PKK in northern Iraq early on Monday, the army said.
There was no immediate claim of responsibility, but Interior Minister Efkan Ala said the name of the group behind the attack would likely be announced on Monday after initial investigations were completed.
Turkey has imposed curfews in several flashpoints in the southeast since August to root out Kurdish militants linked to the PKK.
The swoop caused immediate concern in Washington and Brussels amid the intensifying worries over the climate for freedom of expression in Turkey.