Turkey’s police have detained six more suspects in connection with the attack at Istanbul’s airport that killed at least 44 people.

Friday the suspects were detained in simultaneous raids in the city a day earlier. All six were foreign nationals, the agency said without specifying their nationalities.

“One of the suspects had been in contact with the suicide bombers while the five others “acted jointly” with him or her.” Police said

Authorities have arrested 30 other suspects since the attack, including 14 foreign nationals.

Three militants armed with assault rifles and suicide bombs stormed Istanbul’s Ataturk Airport on June 28.

No one has claimed responsibility for the attack, but Turkish officials say they believe it was the work of the Islamic State group.