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GAZA CITY, Gaza Strip-- A powerful explosion ripped through a Hamas military compound in the Gaza Strip on Wednesday, wounding more than a dozen people, including women and children, Hamas militants said.

In a statement Hamas did not give a cause for the blast in the southern Gaza town of Rafah. The Israeli military said it wasn't involved, which suggests that the explosion was an accident.

The blast shook through a densely crowded neighborhood in Rafah. Hamas said five children, three women and five other people were lightly wounded, all by flying glass shrapnel.

The Gaza-based Palestinian Center for Human Rights has repeatedly called on the territory's Hamas rulers not to store explosive materials in civilian areas. It said a similar explosion in August wounded 58 people and destroyed seven houses.

Israeli jets often target Hamas military installations and rocket launchers. Internal explosions are also common, with bombs and rockets going off prematurely.

Hamas, an Iranian-backed militant group, has controlled Gaza since seizing power from forces loyal to Palestinian President Mahmoud Abbas in a violent takeover in June 2007. Abbas now controls the West Bank, leaving the Palestinians with rival governments in the two territories they claim for a future state.

In the West Bank on Wednesday, Palestinians said Jewish settlers set fire to a girls school near the northern city of Nablus. The school was found vandalized with Hebrew graffiti on the wall reading "regards from the hills." Jewish settlers live on hilly outposts nearby.

The Israeli military said a complaint had been received from Palestinians and Israeli police were investigating. The fire appeared to cause minor damage.

The incident appears to be the latest action in a campaign extremist Jewish settlers call the "price tag." They say it is their response to moves by the Israeli government to remove unauthorized settlements or restrict settlement construction.

Two weeks ago, arsonists torched a West Bank mosque, scrawling "revenge" on a wall in Hebrew and charring copies of the Muslim holy book.

The West Bank government is conducting peace talks with Israel in hopes of reaching a peace agreement establishing an independent Palestinian state. To advance that goal, Abbas' prime minister, Salam Fayyad, has launched an ambitious economic development plan to prepare the way for independence.

The Palestinian transportation minister said Wednesday that his ministry has finished designing an airport in the West Bank. Sadi Kruns said construction on the $340 million project -- a centerpiece of the Palestinian development plan -- should get under way by the middle of next year.

"We rely on the international community, particularly the U.S. and European Union ... to provide the required funds and to remove the obstacles that might emerge," he said.