Palestinian President Mahmoud Abbas condemned the attack on the Egyptian–Gaza border on Sunday that left 16 Egyptian soldiers dead, in a telephone call with President Mohamed Morsi on Monday.

The attack was carried out by unknown assailants, and investigations have been launched by Egyptian military prosecutors to determine the culprits.

Abbas stressed that the attackers must be captured "for Egypt to remain secure on all levels," and confirmed that Palestinian authorities will stand by Egypt against "terrorism".

During the phone call, the Palestinian president gave his condolences to the president, the armed forces, and the Egyptian people and to the families of the dead.

Earlier on Monday, the Egyptian armed forces issued an audio statement on state television accusing the assailants of reaching the borders through the Gaza tunnels.

On Sunday, Hamas, which has governed the Gaza Strip since 2007, released a statement condemning "this ugly crime which killed a number of Egyptian soldiers and extends its deep condolences to the families of the victims and to the leadership and the people of Egypt."

The Islamist group later denied circulating rumours that Hamas might have been behind the attack.