Palestinian President Mahmoud Abbas announced three days mourning starting Tuesday for 16 Egyptian soldiers who lost their lives following Sunday's attack on Egypt's border with Israel.

Abbas ordered flying the Palestinian flag at half-mast at national institutes, embassies and consulates all over the world. 

On Sunday evening an attack on the Egypt-Gaza border involved a military vehicle, reportedly hijacked earlier, which exploded around 7pm. Others were injured after the attackers opened fire on them. A total of 16 Egyptian border guards were killed, with seven others injured.

In Gaza, a post-Iftar prayer was held by the Egyptian embassy for those killed.

Egypt's president  on Monday announced three days of mourning for the Egyptian soldiers.

A military funeral is scheduled to take place on Tuesday to be attended by both President Morsi and Minister of Defence Hussein Tantawi by the Memorial of the Unknown Soldier in Nasr City.

Investigations by authorities into the attack are underway, and no group has claimed responsibility.