DHAKA: Israel has agreed to a 7-hour humanitarian cease-fire, according to the Israel Defense Forces, but a spokesman for Hamas says it's a no go.

The cease-fire is expected to start at 10 a.m. local time (3 a.m. ET) Monday, the IDF said in a statement. It would not apply to the areas in which Israeli soldiers are currently operating.

"The IDF will respond to any attempt to exploit this window to harm Israeli civilians and IDF soldiers," the forces said in a statement.

Previous cease-fires have unraveled early and this one might not even get off the ground as Hamas has not agreed to it, a senior spokesman for Hamas told Al-Aqsa TV.

He spoke Sunday, the same day the United States and the United Nations used the strongest language yet in condemning the latest strike on a U.N.-run shelter in Gaza, with Washington calling the attack "disgraceful."

At least nine people at the school, which was being used as a shelter for about 3,000 people, were killed in the shelling.

The IDF said that it targeted three Palestinian Islamic Jihad members riding a motorcycle in the vicinity of the school.

The IDF said it is reviewing the consequences of the strike but didn't say if the suspected militants were hit.

U.N. Secretary-General Ban Ki-moon said in a written statement that the attack was "yet another gross violation of international humanitarian law."

He demanded a swift investigation into the attack, in which there was an explosion just outside the main gate of the school. He called it a "moral outrage and a criminal act."

The United States, in a statement issued by the State Department, said it was "appalled."

"We once again stress that Israel must do more to meet its own standards and avoid civilian casualties," spokeswoman Jen Psaki said in a written statement. "The suspicion that militants are operating nearby does not justify strikes that put at risk the lives of so many innocent civilians."

An IDF spokesman reiterated Israel's point that militants try to use places where civilians congregate as cover.

"Hamas made a special effort during the past few weeks to fire from U.N. facilities," Brig. Gen. Moti Almoz told CNN.

Thousands of Gaza residents had flocked to the shelter to escape weeks of violence -- only to encounter more bloodshed, reports CNN.

"The dead and wounded in Rafah are still under the rubble and in the streets," Palestinian Health Ministry spokesman Dr. Ashraf el-Qedra said earlier.

Chris Gunness, spokesman for the U.N. Relief and Works Agency, tweeted that the school was sheltering almost 3,000 internally displaced people.

The U.N said nine people were killed, while the Palestinian Health Ministry put the figure at 10. At least 27 people were wounded

BDST: 0848 HRS, Aug 4, 2014