JERUSALEM (AFP) - Pope Francis on Monday made an impromptu stop at a memorial for Israeli civilians killed in deadly militant attacks as he visited the national cemetery in Jerusalem.

The unscheduled visit to the stone monument with black marble plaques in memory of the dead, which is located inside Mount Herzl cemetery, came just after Pope Francis had laid a wreath on the grave of Theodore Herzl, founder of modern Zionism.

The unscheduled visit reportedly took place at the personal request of Israeli Prime Minister Benjamin Netanyahu, army radio reported.

It came after four people were killed on Saturday, including two Israelis, when a gunman opened fire on the Jewish Museum in Brussels, prompting the pope to say he was "profoundly saddened" as he landed in Israel on the final leg of his Middle East tour.

On Sunday, the pope made an unscheduled stop by the West Bank barrier, climbing out of his open jeep to pray, his forehead and hand resting against the wall, in a powerful show of support for Palestinians.

After visiting the cemetery, Pope Francis went directly to neighbouring Yad Vashem Holocaust memorial.

Earlier at the Al-Aqsa mosque compound, the third holiest site in Islam, Pope Francis called for Christians, Jews and Muslims to "work together" for justice and peace.

"May we work together for justice and peace," he said at the sprawling plaza, which is also considered sacred by Jews because it was the site where their two Jewish Temples once stood.

As he toured the compound accompanied by the Grand Mufti of Jerusalem, Mohammed Hussein, he was surrounded by a large crowd of Catholic and Muslim officials, as Vatican security guards and Israeli police looked on.

Entering the exquisite blue-tiled Dome of the Rock with its landmark golden cupola, which is used as a place of worship for women only, the pope first removed his shoes. He then walked down towards the smaller, silver-domed Al-Aqsa mosque - Arabic for the "furthest mosque" - which is considered the third holiest shrine within Islam. It is the site where Muslims believe Prophet Mohammed ascended to heaven.

Located at the south-eastern edge of the Old City, the compound is known to Muslims as Haram al-Sharif or the Noble Sanctuary, and to Jews as the Temple Mount.

For Jews, it is the holiest site in Judaism but they are forbidden by law to pray there, praying instead at the adjacent Western Wall, the last remnant of the retaining wall that supported the second Temple complex.

It is currently the holiest site at which Jews can pray and was also to be visited by the pope immediately after his tour of Al-Aqsa.