Masked gunmen on Saturday morning blew up large parts of the American International School in the Gaza Strip after stealing equipment and furniture.
In another incident also in the Gaza Strip, a Palestinian writer and journalist was moderately wounded during armed clashes clashes between his family and Hamas gunmen.
No group claimed responsibility for the predawn attack on the school, but Palestinian Authority security sources said they did not rule out the possibility that it was carried out by a local al-Qaida-linked group.
"The same people who have been attacking Internet cafes and music shops are also behind this despicable attack," the sources told The Jerusalem Post. "This is the only international school in the Gaza Strip and it's one of the most important academic institutions."
The attack on the private school, which was established in 1995, is not the first of its kind. In 2004, Palestinian gunmen fired a homemade rocket that landed near the school playground.
Last year, unidentified gunmen kidnapped two staff members, one Dutch and the other Australian. The two were later released unharmed. Since then all the foreign teachers have left, leaving the school under exclusive Palestinian control.
No one was injured in the attack, but heavy damage was caused to the building, which is located in the northern Gaza Strip. The attackers overpowered a number of guards before detonating a series of explosive charges inside the school.
School director Ribhi Salem condemned the attack as "disgraceful and immoral," saying those behind it were trying to drive away educated and skilled manpower.
"They want all the good people to leave the Gaza Strip," he said. "We urge the Palestinian Authority leadership to intervene to stop the this phenomenon."
Salem said there were only 300 Palestinians studying at the school, half of the number when it was first opened. "All those working in the school are Palestinians and the funding comes only from Palestinians," he pointed out. "The school has even been built on Palestinian land. We don't know why anyone would want to destroy such an important academic institution. What are they trying to achieve?"
PA Information Minister Mustafa Barghouti also issued a statement strongly condemning the attack. "The explosion seems to be an attempt to undermine national unity and the Palestinian people," he said.
"The continued encroachment on public and private property during this time of internal security chaos serves only the interests of the enemies of the Palestinian people. The government has a plan to solve the security problems and we will not allow such violations to occur. The relevant authorities will bring the perpetrators to justice."
Jamal Nazal, a Fatah spokesman in the West Bank, said the attack was in the context of attempts by "forces of darkness" to turn the Gaza Strip into a Taliban-style country. He added that those behind the attack were also responsible for bombing Internet cafes, theaters and music shops and for assaults on young women in the Gaza Strip.
Hours after the school was destroyed, Palestinian writer and journalist Ashraf Ajrami was wounded in an exchange of gunfire between members of his family and Hamas militiamen.
Ajrami is a columnist for the PA-funded daily Al-Ayyam.
Ajrami recently wrote an article in which he called for an end to the state of anarchy and lawlessness in PA-controlled areas.
"Palestinians have become the victims of internal violence," he said in an article published in the Ramallah-based English language daily Palestine Times.
"The fight that used to be directed against the occupation has instead turned into destructive infighting that ended the relative peace and quiet," he wrote. "Internal violence has increased, including killings, theft, attacks on property, terrorizing people for political and ideological reasons and violent confrontations between Hamas and Fatah. Today, Palestinian society is simply a mess and there is no law and order. This warns of a bigger and unavoidable catastrophe if the situation remains as it is."
Islam Shahwan, spokesman for the Hamas "Executive Force," said the journalist was wounded when members of his family opened fire at a mosque in the Jabalya refugee camp in the northern Gaza Strip.
According to Shahwan, a Hamas force arrived in the camp earlier in the day to arrest a man from the Ajrami family on suspicion of sexually harassing a married woman. After the man was taken into custody, his relatives responded by shooting at a mosque and members of the Hamas force, he claimed.