Chinese Ambassador Nong Rong was staying at the hotel for the night but had left for an official dinner minutes before the blast. The Minister has sought a report of the incident from Chief Secretary Balochistan.
At least five people were killed and 10 injured in the explosion along the city's Zarghun Road Wednesday.
Interior Minister Sheikh Rasheed confirmed the casualties in the blast.
Deputy Inspector General Police Quetta while talking to newsmen said that it was a bomb blast inside the hotel parking area.
Security forces rushed to the hotel and no one was allowed to approach the site of the explosion.
"There must be some breach in security and that is why an explosive-laden vehicle was able to enter".
Sharing further details on the law and order situation in the country, he said that there were threats for such an attack in Quetta, Peshawar, Karachi, Islamabad and Rawalpindi. "Terrorists want to disrupt peace in Baluchistan".
'A vehicle that was full of explosives exploded in the hotel, ' Ahmad told local ARY News TV. "He was attending a function at another place in the city".
According to reports, at least three have died in the blast, which took place in a parking lot near the Serena Chowk at Sharah-e-Zarghoon in Quetta.
Speaking to the media, IG Balochistan Muhammad Tahir Rai said that police are still gauging the intensity of the blast and how many kilograms of explosive material was used in the blast. Footage on local news channels showed cars in flames, while police said they had opened an investigation.
All the attacks were claimed by the Balochistan Liberation Army. The area has been cordoned off and an investigation is underway to identify the intensity of the blast.
He said the investigation into the bomb blast will take note of loopholes.
The outlawed Tehreek-i-Taliban Pakistan has claimed responsibility for the blast.
When asked whether there were any foreign delegations present inside the hotel when the blast occurred, Shahwani said there was only one "luxurious hotel" in Quetta where envoys and diplomats came to have hi-tea.