Gunmen attacked a five-star hotel on Saturday in Pakistan’s south-western port city of Gwadar, located at the restive province of Balochistan.
Local security forces cordoned off the Pearl Continental Hotel in the port city after the attack by at least three armed men at around 16:50 local time (11:50 GMT).
According to BBC and Reuters, it is unclear how many people were at the hotel when the attack happened.
One official, who spoke on condition of anonymity because he was not authorised to talk to the media, said most guests had been evacuated from the hotel but attackers appeared to have reached the first floor and firing is reportedly continuing around the hotel.
Balochistan Home Minister Ziaullah Langove said there appeared to be casualties but there were no immediate details.
There was no immediate claim of responsibility.
Balochistan, home to a long-running insurgency, is Pakistan's poorest and least developed province.
The province is rife with ethnic, sectarian and separatist insurgencies, and several militant groups operate in the province, including the Pakistani Taliban group or Tehrik-i Taliban Pakistan (TTP), Balochistan Liberation Army and the Sunni Muslim extremist group Lashkar-e-Jhangvi.
Gwadar, which lies on the Arabian Sea, is a strategic port being developed as part of the $60 billion China Pakistan Economic Corridor, which is part of China’s mammoth Belt and Road infrastructure project.