A car bomb blast at a hotel hosting the Chinese ambassador to Pakistan killed four people and injured several others on Wednesday in Quetta, located in Pakistan’s southwestern Balochistan province.

“An explosion has rocked the parking area of the Serena Hotel,” local police official Nasir Malik told Reuters, adding that at least 11 people were injured.

Four people died in the explosion and “several others are in critical condition,” an official at a local civil hospital named Waseem Baig told the news agency.

“A car that was full of explosives exploded in the hotel,” Pakistan Interior Minister Sheikh Rashid Ahmad told the local ARY News TV station.

“China’s ambassador to Pakistan was staying at the hotel, but was not there when the bomb exploded,” Ahmad said.

The bomb exploded “minutes before” Chinese Ambassador Nong Rong returned to the hotel, Pakistan’s Chinese  Embassy told China’s state-run Global Times on Thursday. Nong had met provincial Chief Minister Jam Kamal in Quetta earlier in the day, according to a tweet from Balochistan’s government spokesman, Liaquat Shahwani.

The Pakistani Taliban claimed responsibility for the bombing on Thursday.

“It was a suicide attack in which our suicide bomber used his explosives-filled car in the hotel,” a spokesman for the terror group, known as Tehreek-e-Taliban Pakistan (TTP), wrote in a statement issued to Reuters via text message.

“China strongly condemns this terrorist attack, and we are saddened by the innocent victims,” Chinese foreign ministry spokesman Wang Wenbin said Thursday.

The blast took place at the luxury Serena hotel, situated next to the Iranian Consulate and a provincial parliament building. The hotel is frequented by foreigners and considered safe. Quetta is the capital of Balochistan, a province bordering Iran and Afghanistan that has been the site of a low-grade insurgency by separatist militants for the past decade. The separatists seek a greater share of the province’s native resources, as Balochistan is rich in minerals.

China entered Balochistan in recent years through its infrastructure-building Belt and Road Initiative (BRI). The region is the site of the BRI’s flagship project, a yet unfinished “economic corridor” linking China to Pakistan estimated to be worth $65 billion. Beijing recently expanded a deepwater port in the city of Gwadar, located in Balochistan along the Arabian Sea coast opposite Oman. Gwadar’s port is considered crucial to completing the BRI economic corridor.

While it remains unclear if the Pakistani Taliban specifically targeted Chinese Ambassador Nong during Wednesday’s car bombing in Quetta, Chinese nationals and their interests have previously been singled out for attacks by the Pakistan Taliban and Balochistan separatist groups.