The Palestinian Centre for Human Rights (PCHR) based in Gaza area says the occupation troops entered the southern strip shortly after midnight on Monday.
"Heavy military vehicles and helicopters covered by intense shelling moved into the Khan Yunis refugee camp. During the operation, Israeli forces totally demolished 18 houses and partially destroyed four others leaving around 200 people homeless," said a spokesperson for the organisation.
Witnesses told Aljazeera.net the inhabitants of the houses destroyed or damaged in the attack fled their homes when they heard the Israeli military vehicles approaching the area.
"I had to gather my children and make them walk out in the middle of the night. The children were scared and crying because of all the noise from the tanks," said Umar Ahmad, a resident of Khan Yunis.
"I don't know why they had to do this. We are refugees, we no longer have a home as it has been destroyed by the army."
The PCHR says the ongoing attacks against Palestinian civilians and property by the Israeli occupying forces is unlawful and has no military justification.
About 15,000 people were made
homeless in Rafah in October
The Israeli army's actions contravene the Fourth Geneva Convention, and the collective punishment carried out by the army against Palestinian civilians is also in breach of international humanitarian law.
International law states that an occupying force has to uphold the human rights of an occupied group of people.
In October, the Israeli army launched a massive invasion of the Rafah refugee camp and town near the Egyptian border. Eight Palestinians were killed and nearly 15,000 people were made homeless when soldiers demolished 100 homes.
The invasion and devastation was condemned by the UN and European Union.
Non-governmental agencies and charities working in Gaza say the latest invasion will make life more difficult for refugees in the camps and add further pressure on agencies trying to provide humanitarian aid in the region.
"Families are in dire need of food parcels, but we can't get to them. This latest invasion will make our work more difficult"
Medical Aid For Palestinians, Gaza
Fikr Shaltoot works for the charity Medical Aid For Palestinians(MAP) and is based in Gaza City. She told Aljazeera.net that people there were desperate.
"One of the major problems that we face in the south of Gaza is that MAP is unable to access areas where we have established projects such as mobile health clinics. Families are in dire need of food parcels, but we can't get to them. This latest invasion will make our work more difficult."
Israel said its soldiers destroyed several homes it claimed were used as launching pads to fire mortars at the nearby Gush Katif Jewish settlement.
Earlier today Israeli soldiers shot and killed two unarmed Palestinians, and were searching for a third in southern Gaza.
The army claimed that a group of six Palestinians approached a fence in the northern Gaza Strip that separates the occupied Palestinian area from Israel. The soldiers said they opened fire when the men tried to break through the fence.
Palestinian security sources confirmed that two men had been killed in the security zone east of Bait Hanun at about midnight.
The bodies had yet to be returned by the Israelis, the sources said, adding that they were not known to belong to any resistance group.