Near-simultaneous explosions at around 1:40 am (local time) on Tuesday hit two Istanbul hotels, killing one person and wounding seven, according to reports.
"It appears to be a terrorist attack," city police chief Celalettin Cerrah told Turkish state news agency Anatolia.
The fatality occurred at Pars Hotel in Laleli district, he said.
The other explosion occurred at Holiday Hotel in Sultanahmet.
At around the same time, attackers tried to use explosive devices to detonate fuel storage tanks at the Demiroren Group facility in Esenyurt neighbourhood, CNN quoted company spokesman Tayfun Demiroren as saying.
The bombs exploded but failed to rupture the tanks, he said.
More than 70 people were killed in a string of bombings in Istanbul in November 2003, targeting two synagogues, a British-owned bank and the British consulate.