A Turkish news agency says a small bomb has exploded at a parking lot near a military academy in Istanbul, causing minor damage to a few cars.
The private Dogan news agency reported no casualties caused by the bomb, which went off Tuesday in the mainly-commercial Maslak district, on the European side of the city.
No claim of responsibility was reported, but militant leftist, Kurdish and Islamic groups are active in the city.
The attack comes a day after a police crackdown on radical groups on the Asian side of Istanbul led to a five-hour shootout with a leftist militant that killed three people and injured eight.
Police are on alert for possible clashes with leftist militants on Labor Day on Friday.