A sanitation worker was injured in an explosion on Monday as he was emptying a litter box in a central Istanbul park, the Anatolia news agency reported.
Police said the blast occurred at 9.35am (0635 GMT) as a cleaner picked up a package left at the base of a tree next to a rubbish bin at the park area of the Taksim Promenade.
The cleaner was being treated at a nearby hospital. It was not clear how badly he was injured.
Police sealed off a large area around the site of the explosion.
Istanbul's police chief said the blast was caused by a small bomb.
Turkey has been on edge this summer by a wave of blasts across the country, some of them caused by bombs.
Earlier, the Anatolia news agency quoted police as saying two people had been killed and 10 injured after an explosion ripped through a bus travelling in Turkey's southern Mediterranean province of Antalya late on Sunday.
The explosion sparked a fire, which was later extinguished.
Antalya police chief Naciye Ekmekcibasi told Anatolia that the authorities were still investigating what caused the explosion.
The bus, carrying 20 people on board, was travelling on a road between Antalya city and the nearby town of Manavgat, which are both major tourist centres.
The blast occurred in a baggage rack over the passengers' seats, Anatolia said, adding that the impact scattered pieces of metal over a vast area.