Six soldiers and a civilian were wounded when an explosives-laden car blew up near a military base in Turkey's biggest city Istanbul on Thursday, authorities said, the latest in a spate of bombings this year.

The parked car exploded in a road in Istanbul's Sancaktepe neighbourhood as a bus carrying military personnel passed by, the army said in a statement. The civilian driver was among the injured, it said.

The blast sent a large plume of smoke up over Sancaktepe, which is near a military airfield on the Asian side of the city, well removed from Istanbul's historic centre.

"Our citizens are being treated at the hospital. Seven people have light injuries due to shattered glass, six of them soldiers, one civilian," Sancaktepe Mayor Ismail Erdem told CNN Turk.

The car exploded at around 5 pm (1400 GMT), a time when military personnel usually leave the nearby base to go home, according to the broadcaster.

Turkey has suffered a series of bombings this year, including two suicide attacks in tourist areas of Istanbul blamed on Islamic State and two car bombings in the capital, Ankara, which were claimed by a Kurdish militant group.

A Nato member and a candidate to join the European Union, Turkey is participating in the US-led coalition fighting Islamic State in Syria and Iraq, and also battling a militant insurgency in its largely Kurdish southeast region.

The Kurdistan Freedom Hawks (TAK), an offshoot of the outlawed Kurdistan Workers Party (PKK) militant group, has claimed responsibility for two other car bombings this year, both of them in Ankara.

The first, a car bomb that targeted soldiers, killed 29 people in February. The second, at a transport hub a month later, killed at least 37 people.

TAK says it split from the PKK, which has waged a three-decade insurgency against the Turkish state, but experts who study the two militant groups say they retain close links.