The explosion happened at Sabiha Gokcen airport on the Asian side of Istanbul.

Reuters, AFP/Istanbul

An explosion at Istanbul's second-largest airport on Wednesday killed one cleaner on an airplane and injured another, Dogan news agency said, adding authorities were investigating whether the blast was caused by a bomb.

Budget carrier Pegasus said the explosion at Sabiha Gokcen airport on the Asian side of the city occurred at 2:05 am (0005 GMT), when no passengers were in the area. It said its operations at the airport were continuing normally.

Airport cleaner Zehra Yamac, 30, died of head wounds hours after the blast on the airport tarmac, CNN-Turk and NTV television reported.

The explosion took place just outside the terminal building where planes park for their passengers to embark and disembark. 

Turkey’s private carrier Pegasus Airlines said in a statement the explosion took place next to one of its planes on the tarmac while the two cleaners were nearby.

“There were no passengers either on the plane or on the stairway. Sabiha Gokcen airport is continuing its normal operations,” Pegasus said.

The wounded victim was also a cleaner. Yamac was hospitalised but died of her wounds.  

Sabiha Gokcen airport, named after Turkey’s first female fighter pilot, is the second international airport in Istanbul after Ataturk Airport on the European side of the city. 

Sabiha Gokcen, which hosts flights both to domestic and numerous international destinations often with budget airlines, is now fully owned by Malaysian Airports Holding.

“We are working very closely with the Turkish government and our counterparts to facilitate the investigation, and we await their official report on it,” Dato’ Azmi Murad, the executive director of Sabiha Gokcen said in a statement.

Police armed with rifles and protective vests imposed tight security at entrances to the airport after the blast, searching vehicles while a police helicopter circled overhead, state-run Anadolu Agency said.

Anadolu earlier reported that one of the cleaners suffered a head wound, while the other was wounded in the hand.

Police declined to comment on the incident.

The airport said investigations into the cause of the blast were ongoing, and that air traffic was operating normally.

Bomb attacks by Kurdish, leftist and Islamist militants are common in Turkey. A three-decades-old conflict between the state and the militant Kurdistan Workers Party (PKK) has flared up in Turkey's mainly Kurdish southeast since the collapse of a ceasefire in July.

According to its website, the airport served around 26mn passengers in the first 11 months of the year, less than half the number at the main Ataturk airport on the European side of the city.