Turkey's Justice Minister Bekir Bozdag says at least 31 people have been killed and some 147 wounded in the attack on Istanbul's Ataturk airport.
Another senior government official says the death toll could climb much higher.
The senior official at first said close to 50 people had already died, but later said that the figure was expected to rise to close to 50.
The official, who spoke on condition of anonymity in line with government protocol, also said all initial indications suggest the Islamic State group was behind the attack.
Turkey has suffered several bombings in recent months linked to Kurdish or Islamic State group militants.
AT&T says it will waive or credit charges incurred for consumer or business calls placed by AT&T’s customers from the United States to Turkey between June 28, 2016 to June 30, 2016, in the local time zone. This includes landline, texting, and mobility (Postpaid and GoPhone) calls.
(The Associated Press contributed to this report.)
