The provincial interior minister, quoted by Xinhua, said at least three militants attacked a five-star hotel with gunfire. A security agent was killed, according to local media.
An official who spoke on condition of anonymity because he was not authorized to make statements to the press told Reuters that most of the hotel's guests had been evacuated but the attackers seemed to have reached the first floor of the building.
Fireworks are taking place within the Pearl Continental Hotel for nearly two hours, and it is unclear if there are victims, local police chief Aslam Bangulzai said, quoted by dpa. Police and paramilitary forces surrounded the hotel.
Gwadar Port is part of a $ 62 billion Chinese project to build trade routes to the Middle East, Africa and Europe, the German media agency reports.
Muslim militant violence has been intensifying in recent weeks.