UMM NASER, Gaza Strip (AP) – March 27 -- An earth embankment around a sewage reservoir collapsed Tuesday, spewing a river of waste and mud that killed five people and forced residents to flee from a village in the northern Gaza Strip, officials said.

A local Palestinian official blamed the disaster in Umm Naser on shoddy infrastructure, and U.N. officials said they had been warning of a catastrophe for more than two years.

Emergency workers poled between the houses on flat-bottomed boats and chickens fled their coops to perch high on power lines. The stench of sewage mixed with mud and dead animals filled the air, causing people to cover their mouths.

Ziad Abu Farya, head of the village council, described the scene as "our tsunami."

A 2004 U.N. report warned that the sewage facility was at maximum capacity and flooding was inevitable unless a new waste treatment plant was constructed. It said the effluent lake was a breeding ground for mosquitoes and waterborne diseases, posing a serious health hazard.

Efforts to build a new waste treatment plant were repeatedly hampered by fighting between Israel and the Palestinians. Stuart Shepard, of the UN Office for the Coordination of Humanitarian Affairs, said that since the report was published, international funding for a new plant had been secured but construction could not go ahead because the area was too dangerous.

Umm Naser is about 300 yards from the border with Israel in an area where Palestinians have frequently launched rockets into Israel, and Israeli artillery and aircraft have fired back.

Fawzi Barhoum, a Hamas spokesman, blamed the international sanctions imposed on the Palestinians after Hamas' victory in elections in January 2006 for the condition of Gaza's infrastructure. But Shepard said the Umm Naser project had not been affected by the boycott.

Two women in their 70s, two toddlers and a teenage girl died in the sudden flood, and 25 people were injured, said Dr. Muawiya Hassanin of the Palestinian Health Ministry. At least 25 houses were completely submerged.

Fadel Kawash, head of the Palestinian Water Authority, said that the level of sewage in the pool had increased over the past few days, creeping up the earth embankments around the pool until one collapsed, "causing the sewage to pour toward the village."

Rescue crews and gunmen from the militant Islamic group Hamas rushed to the area to search for people feared buried under the slide of sewage and mud. Most residents fled or were evacuated.

Angry residents drove reporters out of the area and mobbed government officials who arrived at the scene. When Interior Minister Hani Kawasmeh arrived to survey the damage, his bodyguards fired in the air to disperse the crowd.

"We lost everything. Everything was covered by the flood. It's a disaster," said Amina Afif, 65, whose small shack was destroyed.

Shepard, of the U.N. Office for the Coordination of Humanitarian Affairs, said the wave of waste released Tuesday sent the health risks even higher.

"It is an extremely serious situation," he said.

The Israeli army offered humanitarian assistance to help clean up the spill. There was no word on whether the offer had been accepted.