Bystanders mourn as the of coffins of soldiers are carried by an ambulance during a funeral at the tomb of the late President Anwar al-Sadat and the Unknown Soldier monument in Cairo.

Cairo -

Egyptian President Mohammed Morsi did not attend a funeral Tuesday in Cairo for the 16 soldiers killed in an attack on an army outpost near the Gaza Strip.

The military funeral was led by Field Marshal Hussein Tantawi, the defence minister and head of the Supreme Council of the Armed Forces.

Presidential spokesman Yasser Ali said Morsi had sent Tantawi on his behalf so that presidential security measures would not be required.

“The president was anxious to ensure public attendance at the military funeral. He decided not to attend in order to keep it a mass event and avoid public attendance being obstructed by security measures,” Ali told reporters.

Morsi instead visited survivors of the attack at a Cairo military hospital.

Thousands of Egyptians were at the ceremony, which was broadcast live on state television. Some of the mourners shouted slogans against Morsi and his Muslim Brotherhood for their links to the Palestinian movement Hamas.

The funeral began at an army mosque in the eastern Cairo area of Nasr City where the bodies of the slain soldiers were draped in the national flag.

Morsi on Monday announced three days of national mourning for the soldiers who were killed by gunmen in Bedouin attire on Sunday in the Rafah border town in the Sinai Peninsula.

Morsi, who took office on June 30, promised a harsh response to the attack and said the military would bring Sinai under control.

The Egyptian forensic medical service will examine the remains of assailants handed over by the Israeli authorities on Wednesday morning, according to a forensic medicine official quoted by state-run newspaper Al Ahram.

Dr Ashraf al-Rifai told the newspaper that the service had received five body bags containing dismembered human remains and that forensic practitioners would examine them to retrieve DNA and seek to establish their identity.

An Israeli army spokeswoman had earlier said that Israel handed six bodies over to Egypt on Sunday night, and that most of them had been wearing suicide bomb belts.

Egypt sealed off Sinai after the attack, and announced the indefinite closure of the Rafah border crossing - Gaza's only outlet to the outside world.

State television reported on Tuesday evening that the military was moving heavy equipment into the Rafah area to block the exits of smuggling tunnels between Egypt and Gaza.

The Muslim Brotherhood has claimed that the Israeli intelligence service Mossad may be behind the attack.

“This crime can be attributed to the Mossad, which has been seeking to abort the (Egyptian) revolution since it started,” said the group in a statement.

Israeli Foreign Ministry spokesman Yigal Palmor said: “This is not even an accusation. This is someone on automatic pilot just sending out their generic blasting of Israel. It's completely ridiculous.”

“It contradicts the Egyptian government's statements and it deserves no serious comment by anyone,” he told dpa.

Israeli Foreign Minister Avigdor Lieberman told Israel Radio that the Egyptians knew the attackers were radical Islamists.

Al Ahram cited an unnamed security source as blaming the incident on a militant group led by a fugitive Palestinian, which the source said had attacked security buildings in Sinai in the past few months.

“This group, made up of around 500 people, comprises members from different Egyptian governorates and some Arab countries,” said the source.

The newspaper also quoted presidential spokesman Ali as saying that there was as yet no definite information as to the identity of the assailants.

The attack has renewed calls in Egypt for the amendment of a 1979 peace treaty between Egypt and Israel setting limits on the presence of Egyptian military forces in Sinai.

Over the past year, Islamist militants in Sinai are believed to have been responsible for several attacks on a pipeline that exports gas to Israel as well as raids on police stations.

Egypt has been trying in the past months to secure the peninsula as turmoil and soaring crime rates nationwide followed the ouster of president Hosny Mubarak in a popular revolt in February 2011. - Sapa-dpa