They were in Idlib province near the Turkish border, according to the Syrian Observatory for Human Rights.

BBC: US woman Nicole Mansfield killed fighting in Syria

Elsewhere, Syrian security forces purportedly "seized" explosive, weapons and ammunition in Homs and in Idlib province.

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They were filming a documentary about Syrians fleeing to Turkey and were staying with activists in Idlib province.

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State TV said military forces conducted operations around Damascus and in the provinces of Hassaka, Daraa, and Idlib and Aleppo.

NPR: Syrian Activists: Strikes, Clashes Across Country

To date, only four of Syria's 14 governorates constitute the major hubs of the protest movement: Homs, Hama, Idlib and Daraa.

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Their father Michael sneaked out of Idlib the same night, and the three were reunited the next day in southern Turkey.

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The editor of TimeTurk says the video was taken near the Syrian city of Idlib 30 minutes before Ziya was handed over to Turkish authorities.

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Activists in the city of Maaret Nouman in Idlib province reported that a group of U.N. observers arrived "suddenly" on Friday and met with residents there.

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The observers are in Homs, Hama, Daraa, Idlib and Damascus.

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Eighteen of the deaths were in Idlib, the LCC said.

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Olivier Voisin, 38, died in a hospital in the city of Antakya in Turkey where he had been treated for injuries sustained in the Syrian province of Idlib on 21 February.

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"They were shot dead during an ambush in the Idlib region and the army found them with maps of military positions, " Rami Abdel Rahman, director of the monitoring group, told the AFP news agency.

BBC: US woman Nicole Mansfield killed fighting in Syria

Joshua Landis, director of the Center for Middle East Studies and associate professor of Middle Eastern studies at the University of Oklahoma, said Alawites live "cheek by jowl" near Sunnis in Homs, Hama and Idlib province in the west.

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But Turkish authorities said Sunday they had detained nine Turkish citizens with links to the Syrian intelligence agency in connection with the bombings in the border town of Reyhanli, a hub for Syrian refugees and rebels just across from Syria's Idlib province.

NPR: Turkey Says It Won't Be Drawn Into Syria Conflict

"This is a matter of utmost urgency for the United Nations and all efforts are in place to make sure that we get the people on the ground as quickly as possible ... apart from Damascus, we have permanently based observers in Homs, Hama, Daraa and Idlib, so this process will continue, " said Neeraj Singh, the observer team's spokesman, on Sunday.

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