Gunmen have targeted a hotel in the city of Gwadar in southwestern Pakistan.
Reports say they are engaged in a stand-off with security forces.
An official, who spoke on the condition of anonymity, said most guests had fled the complex but that the attackers appeared to reach the first floor of the hotel.
According to The Balochistan Post, at least 10 blasts were heard near the five star Pearl Continental Hotel.
There were reports of four attackers entering the building.
The port city where the hotel is located lies on the Arabian Sea, and is a strategic port being developed as part of the US$60bn (€53.4bn) China-Pakistan Economic Corridor.
Balochistan Home Minister Ziaullah Langove said there appeared to be casualties but did not give any further details.
No groups or individuals have said they are behind the attack.
Ethnic, sectarian and separatist insurgencies have plagued the region with several militant groups operating in the province.
Main image: Fishing boats berth in the bay at Gwadar port in southwest Pakistan's Gwadar in January 2018 | Image: Ahmad Kamal/Xinhua News Agency/PA Images