AMMAN, Jordan -- Syrian government troops fired mortar rounds that slammed into a main market in a town in northern Syria on Sunday, killing at least 20 civilians, activist groups said.
The shells struck Ariha, which is held mostly by opposition fighters, a few hours ahead of iftar, the meal that breaks the dawn-to-dusk fast during the Muslim holy month of Ramadan.
The U.K.-based Syrian Observatory for Human Rights and the Local Coordination Committees, two opposition groups tracking the violence in Syria, said at least 20 people were killed, including two children and two women. It was not immediately clear what triggered the shelling.
Also Sunday, state media said government forces killed nearly 50 rebels in an ambush near Damascus.
Separately, Kurdish rebels freed the local commander of an al-Qaida-linked group in a town near Syria's northern border with Turkey in return for 300 Kurdish civilians detained by the group, as part of an agreement to end rebel infighting that erupted a day earlier in the region.
Infighting between al-Qaida militants and more mainstream Syrian rebels, as well as between Kurds and Arabs, has grown more common in Syria in recent weeks -- part of a power struggle that is undermining their efforts to topple President Bashar Assad.
Bombs dropped in park
CANBERRA, Australia -- Two U.S. fighter jets have dropped four unarmed bombs in Australia's Great Barrier Reef Marine Park when a training exercise went wrong.
The two AV-8B Harrier jets launched from aircraft carrier USS Bonhomme Richard each jettisoned an inert bomb and an unarmed explosive bomb in the World Heritage-listed marine park off the coast of Queensland state on Tuesday, the U.S. 7th Fleet said in a statement Saturday.
The four bombs were dropped in more than 164 feet of water away from coral to minimize possible damage to the reef, the statement said. None exploded.
The jets from the 31st Marine Expeditionary Unit had intended to drop the ordnances on the Townshend Island bombing range but aborted the mission when controllers reported the area was not clear of hazards.
The pilots conducted the emergency jettison because they were low on fuel and could not land with their bomb load, the navy said.
Lew in Greece for talks
ATHENS, Greece -- U.S. Treasury Secretary Jacob Lew urged Greece on Sunday to continue its efforts to stabilize its debt-ridden economy and capitalize on the sacrifices already made "to ensure prosperity and growth for generations to come."
Mr. Lew was on a one-day visit to Greece after attending a Group of 20 summit in Russia. Mr. Lew said the U.S. is closely following Greece's efforts to end its economic crisis.
UAE: Egypt-based hacking
ABU DHABI, United Arab Emirates -- Officials in the United Arab Emirates on Sunday said they have thwarted an attempt by Egypt-based hackers to bring down UAE government websites in apparent retaliation for backing the forces that ousted Islamist President Mohammed Morsi.
The UAE has emerged as a leading Arab supporter of the military-led authorities in Egypt since Mr. Morsi was toppled earlier this month. The UAE also is a fierce opponent of Mr. Morsi's Muslim Brotherhood, charging supporters of the Islamist group with plotting to overthrow the UAE's ruling system.