Massive boulders weighing dozens of tons smashed down on an Egyptian shanty town this morning on the outskirts of the capital killing at least 18 people.

At least eight boulders, some the size of small houses, fell from the towering Muqattam cliffs outside Cairo and buried some 50 homes in the massive Manshiyet Nasr slum, one of the shanty towns ringing Africa's most populous city.

Officials said that 35 people were injured and many are still believed to be buried under the hundreds of tons of rock that fell.

Agony: men and women screamed in grief - some had lost all family members

'My whole family is underneath the rock,' sobbed Anwar Ragab, as he watched a body being pulled from under the rock.

'I don't know what to do, I can't do anything - I just want my children back.'

The remains of the town were covered by a thick layer of dust and the scene was chaotic as men and women screamed in grief. People tried to lift the massive rocks by hand, calling out the names of relatives and family members stuck under the debris.

Police with sniffer dogs searched the rubble, but six hours after the disaster, there was no sign yet of heavy machinery to clear it.

Angry residents yelled at police and government officials at the site, blaming them for the tragedy.

Search: six hours after the fall, heavy lifting equipment had still to arrive, forcing men to lift rocks and rubble by hand as they called their relatives' names

The government issued a statement saying that survivors would be transferred to new housing for the night and given all necessary aid.

'We are following the case step by step and providing the care and comfort for the residents,' Prime Minister Ahmed Nazif said.

'We would like to remind people the danger of building informal housing in dangerous areas.'

Danger: despite warnings, the government had not yet resettled residents

The boulders came crashing down at 7am, when most residents were still sleeping after waking earlier to eat ahead of the daytime fast of Islam's holy month of Ramadan.

'I couldn't find my house this morning,' said Mustafa Abdel-Fatah, who spent the night at a friend's place elsewhere. 'I could only see rocks on top of everything.'

Haidar Baghdadi, the parliamentarian for the region, told Al-Jazeera news channel that buried residents were calling for help from under the rubble using cell phones.

The representative added that the area was known to be dangerous and the residents were supposed to be resettled to government housing. He also criticized the lack of government emergency response.

Devastation: an Egyptian man sits in the rubble of his home

'We should have removed these rocks five years ago to protect the people underneath or moved the people,' he said, blaming the Housing Ministry for the disaster.

Rock slides periodically take place on the edges of the brittle limestone Muqattam hills outside Cairo. The base of the cliffs are also home to dozens of slums built by impoverished migrants from countryside looking for work in the city.

Hani Rifaat, a journalist for a local daily who has long been following the case said that just two months ago other rocks fell prompting residents to ask the government for help, but nothing happened.

'The reason the rocks keep falling is because there is no sewage system and their waste water is eating away at the mountain,' he said from the site of the disaster.

In 1994, some 30 people were killed in another rock slide in the same area.

Riot police arrive as angry residents blame the government for the tragedy