QUETTA, April 22 (CNA) - At least four people were killed and a dozen others wounded when a bomb exploded at a top hotel hosting the Chinese ambassador in southwestern Pakistan, officials said late Wednesday (Apr 21).

The blast took place in the car park of the Serena - a luxury hotel chain throughout Pakistan - in the city of Quetta, the capital of Balochistan province where the military has been fighting a decade-long low level insurgency.

China's ambassador to Pakistan was staying at the hotel, but was not there when the bomb exploded, said Pakistan's interior Minister, Sheikh Rashid Ahmad.

"A Chinese delegation of around four people led by the ambassador was lodging in the hotel.

"The ambassador was out for a meeting when the explosion took place," he added.

Provincial Home Minister Ziaullah Lango said the envoy was fine.

Lango told reporters: "I just met him. He is in high spirits," adding the envoy would complete his visit to Quetta on Thursday.

"An explosion has rocked the parking area of the Serena Hotel," police official Nasir Malik told Reuters, saying 11 people had been wounded. An official at a local civil hospital, Waseem Baig, said four people had died, and "several others are in critical condition".

"A car that was full of explosives exploded in the hotel," Ahmad told local ARY News TV.

Senior police official Azhar Akram said officers were trying to determine whether the bomb was planted in a vehicle that was parked in the hotel’s parking lot. He provided no further details, saying police were still investigating.

Other security officials said the bomb exploded minutes after a car entered the parking lot, and authorities were investigating to determine whether it was a suicide attack.

Hours after the attack, the Pakistani Taliban in a statement claimed responsibility, saying it was a suicide attack. The Pakistani Taliban, or Tehreek-e-Taliban Pakistan, is a separate insurgent group from the Afghan Taliban.

"It was a suicide attack in which our suicide bomber used his explosives-filled car in the hotel," a spokesman for the militant group wrote in a text message to a Reuters reporter.

Quetta is the capital of the mineral-rich southwestern Balochistan province bordering Iran and Afghanistan, which has long been the scene of a low-level insurgency by local nationalists, who want more of a share in the regional resources.

It was not clear whether the Chinese ambassador 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 Taliban militants and nationalist insurgents.

The bombing in Quetta came hours after Pakistan and neighbouring Iran opened a new border crossing point in Balochistan to improve trade and economic relations. Baluchistan shares a border with Iran and Afghanistan.

The Pakistani Taliban have been targeting the military and civilians across the country since 2001, when this Islamic nation joined the US-led war on terror following the Sep 11 attack in the United States.

Since then, the insurgents have declared war on the government of Pakistan and have carried out numerous attacks. Pakistan’s militant groups are often interlinked with those across the border in Afghanistan.