- The blast hit Sabiha Gokcen Airport, on the Asian side of Turkey's most populous city
- The cause of the explosion, which occurred in in the plane parking area, is unknown, the airport says
- Ankara's main train station was hit with two deadly bombings in October
"An explosion of unknown cause occurred in the plane parking area of the Istanbul Sabiha Gokcen Airport ... at around 2:00 at night," said a statement on the official Twitter account of the airport, which is on the Asian side of Istanbul.
While the cause of the explosion is not known and may not relate to terrorism, Turkey is thought to have made itself more vulnerable to terrorist attacks since it began allowing the United States to use a Turkish air base to launch airstrikes on ISIS in northern Syria.
On October 10, two bombings outside Ankara's main train station killed more than 100 people. No group claimed responsibility for that attack.
Istanbul, with an estimated population of 14.2 million, is Turkey's largest city. It straddles Europe and Asia across the Bosporus.