Unlock stock picks and a broker-level newsfeed that powers Wall Street.

UPDATE 3-Egyptian mediators try to build on Israel-Hamas ceasefire

* Ceasefire ended 11 days of fighting

* No violations reported on Saturday

* Blinken to visit Israel, PA next week

* Egyptian mediators engage in shuttle diplomacy (Adds UN Security Council, EU, more Israeli comment)

By Nidal al-Mughrabi and Dan Williams

GAZA/JERUSALEM, May 22 (Reuters) - Egyptian mediators sought to reinforce a day-old ceasefire between Israel and Palestinian militants on Saturday, and aid officials appealed for a period of calm to start tackling a humanitarian crisis in Gaza after 11 days of fighting.

The ceasefire, which began before dawn on Friday, was still holding on Saturday evening, enabling officials to start assessing the scale of the damage.

Despite confrontations between Israeli police and Palestinian protesters at a Jerusalem holy site on Friday, there were no reports of Hamas rocket launches from Gaza or Israeli air strikes on the Palestinian enclave overnight or on Saturday.

Rockets fired by Hamas and other Islamist militant groups paralysed towns in southern Israel during the hostilities, and caused widespread panic, but did much less damage than the bombardment of the Gaza Strip.

Palestinian officials put reconstruction costs at tens of millions of dollars in Gaza, where medical officials said 248 people were killed in the fighting.

A senior U.N. official who toured the densely populated coastal enclave on Saturday warned of increased health risks and widespread despair after homes, roads and other vital infrastructure including hospitals were damaged or destroyed.

"Everybody just needs to stand down and not to engage in any provocative moves," Lynn Hastings, U.N. Humanitarian Coordinator for the Palestinian territories, said in a rubble-strewn area of Gaza City where she spoke to survivors.

Economists said Israel's recovery from the COVID-19 pandemic could be curbed by the hostilities and medics said rocket attacks had killed 13 people in Israel before the ceasefire.

After mediating the ceasefire with U.S. support, Egypt sent a delegation to Israel on Friday to discuss ways of firming up the truce, including with aid for Palestinians in Gaza, Hamas officials told Reuters.

The delegates have since been shuttling between Israel and Gaza, and on Saturday met Palestinian President Mahmoud Abbas in the city of Ramallah in the occupied West Bank, an aide to the Palestinian leader said.

A source familiar with planning said U.S. Secretary of State Antony Blinken would visit Israel and the West Bank on Wednesday and Thursday, hoping to build on the ceasefire. Mahmoud, however, has little influence in Gaza, which is ruled by Hamas.