ISLAMABAD -- Five Chinese nationals and one Pakistani were killed in a terrorist attack in Pakistan's northwestern Khyber Pakhtunkhwa (KP) province on Tuesday, the Chinese Embassy in Pakistan confirmed.

The attack happened at about 1:00 pm local time (0800 GMT) when a vehicle from the Dasu Hydropower Project, being constructed by a Chinese company in the province, was attacked by terrorists, the embassy said in a statement.

"The Chinese embassy and consulates in Pakistan strongly condemn this terrorist act, express deep condolences for the victims in both countries and extend sincere condolences to the relatives of the victims," the statement said, adding that the Chinese side has been working with the Pakistani side to make every effort to deal with the aftermath of the incident.

The incident happened in the Shangla area of the province, where the attacker rammed an explosive-laden vehicle into a convoy escorted by five vehicles of security forces, sources from KP's police told Xinhua.

One of the vehicles of the 13-vehicle convoy caught fire and fell into a ravine, following the attack, the sources added.

The area was cordoned off for investigations and the injured are being shifted to hospital.

The Chinese missions in Pakistan have initiated emergency response work as soon as possible, requiring Pakistan to conduct a thorough investigation of the attack, and severely punish the perpetrators, the statement said.

The embassy stressed that practical and effective measures to protect the safety of Chinese citizens, institutions and projects in Pakistan should be taken by the Pakistani side to ensure that similar incidents will not happen again.

"The Chinese embassy and consulates in Pakistan remind Chinese citizens and companies in Pakistan to pay close attention to the local security situation, improve security levels, strengthen security measures, and make every effort to take safety precautions," said the statement.

No group has claimed the attack yet.

The incident has also been condemned by the country's President Asif Ali Zardari who expressed his condolence to the bereaved families and vowed that his country will never let enemies of Pakistan-China friendship succeed in their mission.