The explosion outside the Serena Hotel took place late Wednesday night local time and rescue and security services are carrying out investigations into the incident, Muhammad Akram, a rescue official at the scene of the blast, told CNN.
The Serena Hotel is considered the most secure hotel in Quetta and is typically where international development teams and diplomats choose to stay while visiting.
"This incident occurred after Iftar (breaking of fast). The car was parked in the parking lot of the Serena Hotel," said Balochistan provincial Home Minister Ziaullah Lango, according to Reuters. "One of our police constables is among the injured."
Footage and images from the scene show vehicles ablaze in the hotel's parking lot and thick smoke billowing from the blast.
The Pakistani Taliban, a militant group known as Tehreek e Taliban Pakistan (TTP) claimed responsibility for the bombing. In an email received by CNN, TTP Spokesman Muhammad Khurassani said it was a "suicide attack which was carried out by a TTP bomber via car," and that "further details will be shared soon."
China's Ambassador to Pakistan, Nong Rong, was staying at the hotel but was not there when the bomb exploded, Pakistan's Interior Minister, Sheikh Rashid Ahmad, said Wednesday, according to Reuters.
Lango, the provincial home minister, said the ambassador was "in high spirits" and would continue with his activities Thursday. "He has also said that he will only leave after he has completed his tour," Lango said.
It was not clear whether the envoy or members of his delegation were a target of the attack, but Chinese nationals and their interests in the region have been attacked before by militants.
In 2015, under Beijing's Belt and Road trade and infrastructure scheme, China turned Balochistan's Gwadar into the deepest seaport in the world. The coastal town is now a hub of Chinese investment in Pakistan.
Journalist Saleem Mehsud contributed reporting from Islamabad.