Human Rights Watch said it was investigating the same rebel group that claims it has captured UN peacekeepers for executing captured Syrian soldiers earlier this week.
Peter Bouckaert of the human rights monitoring group said it was investigating the involvement of the "Martyrs of Yarmouk" brigade in a video showing the execution of detained Syrian soldiers posted on the Internet yesterday.
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A student has reportedly shot at his companions and a teacher at an American college.
An eight-year-old girl died suddenly last week after she collapsed in the classroom, suffering from a brain aneurysm.
The 72-year-old had to be helicoptered from the mountain, when he was just a few hours from the summit on Monday.