Syrian government troops trying to relieve a besieged military base in the country’s northwest ambushed a rebel checkpoint on Saturday, killing at least 12 Opposition fighters, activists said.

The Britain-based Syrian Observatory for Human Rights said the Government forces surprised the rebel fighters on the outskirts of the village of Baboulein in Idlib province. The Observatory, which relies on a network of local activists on the ground, said many Opposition fighters were also wounded in the attack.

Rebels have wrested much of the countryside of Idlib and other provinces in northern Syria from regime forces, although government troops still control many military bases in the region from which they launch attacks on Opposition-held areas.

Observatory director Rami Abdul-Rahman said the assault on Saturday was part of Government efforts to re-supply the embattled military base at Wadi Deif outside the town of Maaret al-Numan, which is just north of Baboulein on the Damascus-Aleppo highway.

Rebels have been trying for months to capture the large base at Wadi Deif, from which regime troops regularly pound the now largely abandoned town of Maaret al-Numan with artillery fire. The regime must push convoys through rebel-held territory to prevent the base from running short of troops and supplies.

On Thursday, activists said rebels shot down a helicopter carrying food and supplies to the base, killing the pilot and three other soldiers.

In the northern city of Aleppo, a Government air raid on the disputed Sheikh Maqsoud neighbourhood killed at least three people and injured16 others, the Observatory said. It added that doctors treating the wounded said many showed symptoms of inhaling toxic gas, such as severe vomiting and irritation to the nose and eyes.

Both sides in the Syrian civil war have accused the other of using chemical weapons.

UN probe sought

Syria has asked the U.N. to investigate an alleged chemical weapons attack by rebels in March on the village of Khan al-Assal outside Aleppo. The rebels blame regime forces.

Britain and France want the U.N. to investigate allegations of chemical weapons use in Khan al-Assal and another village, Ataybah, on March 19, as well as the central city of Homs on December 23.

Syria has rejected U.N. Secretary General Ban Ki-moon’s push to expand the U.N. probe to include those other villages.

The Syrian conflict began in March 2011 with largely peaceful protests but has since devolved into a civil war that the United Nations says has killed at least 70,000 people. Hundreds of thousands of Syrians have sought refuge abroad, and millions inside the country have fled their homes to try to find safety elsewhere inside Syria.

International efforts to find a peaceful resolution to the conflict have faltered.

Peace plan

Meanwhile, U.N.-Arab League envoy Lakhdar Brahimi is scheduled to address the U.N. Security Council on Thursday. Mr. Brahimi has not been able to make progress in his mission to push forward a peace plan for Syria first presented in June at an international conference in Geneva.

On Saturday, Syrian state-run daily Al-Thawra accused Mr. Brahimi of being a “false witness.” The daily said he had taken sides in the conflict and that his briefing “will not alleviate the suffering of Syrians.”

Mr. Brahimi angered the Syrian Government in December by saying that the four-decade rule of the Assad family had gone on “too long.”

Italian journalists freed

In Rome, the Italian Foreign Ministry said that four Italian journalists who had been detained in Syria since April 4 have been freed. The ministry did not specify who had detained them or disclose details of their release.

Italian media have reported that the four were a RAI public television reporter and three freelancers who had entered Syria earlier this month with the intention of working by day in Syria and crossing into Turkey in the evening. They were reportedly detained in a rebel-controlled area in northern Syria near the Turkish border.

Several Syrian artillery shells exploded in northern Lebanon on Saturday, as fierce battles continued between Syrian Opposition fighters and government troops over control of a strategic supply route.

The second day of shelling in Lebanon’s northern Akar area caused damage but no casualties, a Lebanese police official told DPA.

Abu Raad, a Syrian Opposition activist, said the cross-boarder violence comes as Syrian Government troops backed by fighters from the Lebanese Shiite movement Hezbollah were trying to regain control of the town of al-Kussair in Syria’s central province of Homs, some 30 km from the Lebanese border.

Al-Kussair is crucial for both warring sides in Syria, as it links a major route with the Damascus highway.

Syrian ambassador in Beirut, Ali Abdul Karim, said in an interview with the Iranian Press TV that the Lebanese Government should take “effective measures” to stop the flow of arms and rebels into Syria.

The Lebanese Government has remained largely impartial toward the two-year conflict in Syria, but this has not prevented the violence from spilling over.

Syria warned last month that its troops would fire into Lebanon if what it called “terrorist gangs” continued to infiltrate Syrian territories to fight alongside the rebels.

Meanwhile, in Damascus, Syrian state media are accusing the U.N.’s envoy of being a “false witness” as he prepares to brief the international body on the country’s two-year old conflict, according to an AP report.

Al-Thawra daily said Saturday that Lakhdar Brahimi has taken sides in the conflict and his briefing “will not alleviate the suffering of Syrians.”

The U.N. and Arab League envoy for Syria is scheduled to address the Security Council on Thursday.

Mr. Brahimi has not been able to make progress in his mission to push forward a peace plan for Syria, first presented in June at an international conference in Geneva. Syria accused him of interfering in its internal affairs.

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