GAZA CITY, Palestinian Territories - Israel was observing a temporary unilateral truce in most of the Gaza Strip on Monday amid world outrage over a deadly strike on a UN school in the besieged Palestinian territory.
But Hamas, the de facto rulers of Gaza, said they would not be reciprocating the announced seven-hour lull and warned residents "to take the utmost caution" when venturing out.
Several previous pauses to allow the battered residents of Gaza to stock up and medics to reach the dead and wounded in no-go areas have come to swift and bloody ends.
Minutes after the lull went into effect at 0700 GMT, 30 people were wounded in a strike on a house in the beachfront Shati refugee camp in Gaza City, Palestinian medics said, demonstrating the fragility of the ceasefire arrangement.
The truce was announced amid a growing chorus of international outrage over an Israeli strike next to a UN school that killed 10 people, among them refugees who had been seeking refugee from the violence.
The army said the seven-hour "humanitarian window" would be observed across all of the Palestinian enclave except east of Rafah on the Egyptian border, where troops were still operating and clashes were under way.
It also said residents of two villages east of Khan Yunis in southern Gaza could return home in another sign of troops pulling back in an apparent unilateral withdrawal.
It warned however that it would "respond to any attempt to exploit this window" through launching attacks against Israeli civilians or soldiers during the truce, which officials said was the eighth that Israel has declared since the confrontation began on July 8.
Hamas dismissed the truce announcement as a publicity stunt, advising people to remain cautious.
"The unilateral ceasefire announced by Israel is an attempt to divert the attention from Israeli massacres," spokesman Sami Abu Zuhri said, referring to the strike on a UN school and a punishing attack on Rafah over the weekend.
Fury over school strike
Sunday's strike on a UN school where around 3,000 homeless Palestinians had been sheltering was the third such incident in 10 days and drew fierce condemnation from around the world.
The Israeli army acknowledged targeting three Islamic Jihad militants on a motorbike "in vicinity of an UNRWA school" in the city, saying it was investigating the consequences.
UN Secretary General Ban Ki-moon called the attack "a moral outrage and a criminal act" and State Department spokeswoman Jen Psaki said Washington was "appalled," demanding a "full and prompt" investigation.
"Israel must do more to meet its own standards and avoid civilian casualties," she said.
French President Francois Hollande described the incident as "unacceptable," and demanded those responsible be held accountable.