Two suspects have been detained over Monday's bombing attack on Chinese engineers at Gwadar port, southwestern Pakistan, Karachi police told Xinhua on Tuesday.

The two Pakistani nationals are under interrogation in Gwadar, said the police without giving more details.

A bomb planted in a parked empty pickup blasted earlier on Monday, causing a passing-by bus damaged, leaving three Chinese engineers aboard killed, nine other Chinese engineers and two local employees injured.

The government and the people of Pakistan have strongly condemned the terrorist attack.

The Foreign Office said Monday that President Pervez Musharraf has expressed outrage and condemnation over the incident.

Musharraf, in his letter to Chinese President Hu Jintao, strongly condemned "this barbaric act of terrorism" and underlined that Pakistan will never allow a few terrorists to undermine Pakistan-China friendship and cooperation.

In the letter, the President expressed deep distress and profound shock over the loss of lives and injuries to Chinese engineers and project personnel and conveyed sincerest condolences to the families who had lost their dearest ones.

"We will do our utmost in providing every assistance and treatment to those injured," the President was quoted as saying.

Immediately after the incident, Musharraf spoke to Chinese Ambassador Zhang Chunxiang through telephone and assured him that strict measures were being taken to ensure the safety and securityof all Chinese nationals working in Pakistan.