Foreign Minister Yang Jiechi Monday said China will consistently support Pakistan's efforts in safeguarding national independence, sovereignty and territorial integrity.

Yang made the remarks in a 40-minute conversation with Pakistani Foreign Minister Hina Rabbani Khar concerning the NATO air attack on two border posts in Pakistan early Saturday morning.

The NATO action left 24 Pakistani soldiers killed and 13 others injured.

A Foreign Ministry spokesman later said that China was deeply shocked by these events and expressed strong concern for the victims and profound condolences to Pakistan.

Spokesman Hong Lei said, "China believes that Pakistan's independence, sovereignty and territorial integrity should be respected and the incident should be thoroughly investigated and be handled properly."

Hong called for a thorough investigation of the incident.

The comments of the ministry come at a time when relations between the U.S. and Pakistan are at their most strained for many years, the Guardian reported.

Pakistan insisted that the NATO attack was unprovoked and lasted for two hours, even though the Pakistani forces had contacted NATO to plead for stopping the firing.

Pakistan Saturday closed the border for supplies to NATO troops in Afghanistan and there is no indication when the border crossing will be reopened.

Half the supplies to coalition soldiers pass by land through Pakistan, the Guardian said. The All Pakistan Oil Tanker Owners Association said it would only resume transport if Islamabad and the Pakistani military accepted an apology for the incident.