CAIRO, Mar. 20 (Reuters) – U.S. Secretary of State Antony Blinken began a tour of the Middle East on Wednesday by holding talks in Saudi Arabia, hoping to secure a ceasefire in the Gaza war as increasing strain shows in Washington's relationship with its ally Israel.

In the Gaza Strip, where hunger is spreading and hopes were dashed for a ceasefire in time for Ramadan last week, residents of Gaza City in the north described the most intense fighting for months around the Al Shifa hospital.

Israel said it had killed 90 gunmen in a battle under way there for a third day. The Palestinian militant group Hamas, which Israel says it wants to eliminate, denied fighters were present and said those killed in the hospital were civilians.

After arriving in Saudi Arabia, Blinken met Prince Faisal bin Farhan, the Saudi foreign minister, and was expected to hold talks with ruling Crown Prince Mohammed bin Salman.

He will go on to Egypt, where he is expected on Thursday to meet the foreign ministers of Egypt, Saudi Arabia, Qatar and Jordan, the Emirati international cooperation minister and the secretary-general of the Palestinian Liberation Organisation.

Fighting has intensified in recent days in northern parts of Gaza captured by Israeli forces early in the nearly six-month-old war, including Al Shifa, once Gaza's biggest hospital, now one of the few even partially functioning in the north.

"We are living through similar dreadful conditions to when Israeli forces first raided Gaza City: sounds of explosions, Israeli bombardment of houses is non-stop," Amal, 27, living about a kilometre from Al Shifa hospital, said via a chat app.

Israel's military chief, Herzi Halevi, said Israeli forces were targeting Hamas leaders who he said were in the hospital compound.

"This is very, very important for pressuring Hamas, it's very important for pressuring the negotiations as well," he said in video remarks released by Israel's armed forces.

On Tuesday, Israeli Prime Minister Benjamin Netanyahu rebuffed a plea from U.S. President Joe Biden to call off plans for a ground assault of Rafah, the city on the southern edge of Gaza sheltering more than half the enclave's 2.3 million people.

Netanyahu told Israeli lawmakers he had made it "supremely clear" to Biden in a phone call "that we are determined to complete the elimination of these battalions in Rafah, and there's no way to do that except by going in on the ground".

Israel says Rafah is the last big holdout of armed fighters from Hamas. Washington says a ground assault there would be a "mistake" and cause too much harm to civilians.

State Department spokesman Matthew Miller said one of Blinken's aims was to discuss with Israeli leaders how to defeat Hamas "including in Rafah, in a way that protects the civilian population, does not hinder the delivery of humanitarian assistance and advances Israel’s overall security."

Miller said Blinken and Prince Faisal had discussed the urgent need to protect all civilians in Gaza and immediately increase humanitarian assistance, and underlined the importance of preparing for the phase following the end of the conflict.

Gazans, ordered into Rafah earlier in the war by advancing Israeli forces, have nowhere further to flee. Israel says it has a plan to evacuate them.

Photo from Reuters