Islamabad, Nov 28 (IANS): The Pakistan Army Monday refused to accept NATO's regret over an airstrike that killed 25 soldiers, and warned that it could lead to serious consequences.

Army spokesperson Major General Athar Abbas said they do not accept NATO's regret and this action can lead to serious consequences, reported Geo News.

NATO's regret over the attack is not enough, General Abbas said.

He said that such incidents in the past three years have left 72 soldiers dead and 250 injured.

As many as 25 Pakistani soldiers were killed and 15 others were injured after NATO helicopters from Afghanistan attacked a border checkpost in Mohmand tribal region near the Afghan border early Saturday. Islamabad promptly decided to stop the passage of NATO supply through Pakistan to Afghanistan-based, NATO-led International Security Assistance Force (ISAF) forces.

The NATO airstrike that killed and wounded dozens of Pakistani soldiers Saturday were "unintended", NATO secretary general Anders Fogh Rasmussen said Sunday.

"This was a tragic, unintended incident. I fully support the ISAF investigation which is currently under way. We will determine what happened, and draw the right lessons," said a statement quoting Rasmussen.

Rasmussen said following "the regrettable incident", he had written to Pakistani Prime Minister Yousuf Raza Gilani to say that the deaths of Pakistani personnel were "as unacceptable and deplorable as the deaths of Afghan and international personnel".