UN to visit three Syria 'chemical attack' sites

U.N. inspectors will travel to Syria "as soon as possible" to investigate claims of chemical weapons use during the country's civil war after President Bashar al-Assad's government granted access to three sites, the United Nations confirmed on Wednesday.

"The Mission will travel to Syria as soon as possible to contemporaneously investigate three of the reported incidents, including Khan al-Asal," U.N. Secretary-General Ban Ki-moon's press office said in a statement.

The announcement came as President Bashar al-Assad’s forces launched an assault on Khan al-Asal, an Aleppo village that was recently captured by rebels and is the site of an alleged chemical-weapons attack.

U.N. spokesman Martin Nesirky said the green light for the investigation followed last week's visit to Damascus by U.N. disarmament chief Angela Kane and the head of the chemical weapons investigation team, Ake Sellstrom, and "the understanding reached with the government of Syria".

Assad’s government and rebels blame each other for a purported March 19 chemical attack on Khan al-Asal that killed at least 30 people.

Nesirky did not provide any details on the other two incidents to be investigated.

Ban appointed Sellstrom at the end of March to investigate the Khan al-Assal complaint, as well as claims by Britain and France of chemical weapons use elsewhere in Syria, where a two-year revolt has descended into civil war.

But diplomatic wrangling and concerns over safety have prevented Sellstrom and his team of experts from entering Syria. The United Nations has been demanding unfettered access to conduct the chemical weapons investigation.

The United Nations says it now has 13 reports, mostly from Britain, France and the United States, of chemical weapons attacks. The Syrian government and the opposition both deny using such weapons. The U.N. inquiry will only try to establish if chemical weapons were used, not who used them.

"The Secretary-General remains mindful of other reported incidents and the mission will also continue to seek clarification from the member states concerned," the U.N. statement said.

On Wednesday, regime troops attacked rebel positions outside Khan al-Assal, while fierce fighting erupted on the outskirts of the village, which the rebels seized on July 22, inflicting heavy losses on the army.

The army reportedly lost 150 soldiers over two days, 50 of them believed to be summarily executed after capture, in an act condemned by the mainstream opposition leadership.

In the central city Homs, regime troops continued to bombard rebel-held neighborhoods.

Earlier this week, Assad’s forces managed to take control of al-Khalidiyeh, a district in the city that had for more than a year been an opposition stronghold.

Fatih Hassoun, the Homs Front Commander in the Free Syrian Army, told Al Jazeera that the fighters retreated from the area as a result of the harsh conditions they lived in.

"The decrease in the numbers of fighters and the many injuries they suffered, in addition to the blockade which was chocking old Homs for more than a year, led to the retreat of our fighters," Hassoun said.

Hisham Jaber, a retired Lebanese army general, told Al Jazeera that he believed the fall of the central city to regime troops was inevitable.

"Homs the city I think it will be taken. The battle will be over within a few day, maybe one week or two weeks," he said.

"We have to remember that we have 8,000 civilians inside Old Homs. [Within the armed] opposition, there is lack of organization, lack of cooperation and lack of centralization."

The Syrian army has been pushing steadily north in recent weeks. With the help of Hezbollah fighters from Lebanon, it took full control of the city of Qusayr in June.

The United States concluded last month that Assad's forces used chemical weapons against rebel fighters. President Barack Obama said last year that any attempt to deploy or use chemical or biological weapons in Syria would cross a "red line."

U.S. congressional panels this month agreed to a White House plan to provide arms to the Syrian rebels.

Syria is one of seven countries that has not joined the 1997 convention banning chemical weapons. Western countries believe it has stockpiles of undeclared mustard gas, sarin and VX nerve agents.

Earlier this month, Russia's U.N. envoy Vitaly Churkin sharply criticized what he described as Western nations' "small propaganda storm in a glass of water" over allegations that the Syrian government has used chemical weapons.

Damascus had been refusing to let U.N. investigators go anywhere except Khan al-Assal. Ban had insisted that Sellstrom's team be permitted to visit at least one other location, the city of Homs, site of an alleged chemical attack by government forces in December 2012.

Rebels seized Khan al-Assal from Assad's forces last week. Syrian state media accused insurgents on Saturday of killing 123 people, the majority of them civilians, during the offensive.

A senior Western envoy said that Syrian opposition leaders, who met informally with the U.N. Security Council on Friday, had pledged to grant to chemical weapons experts access to areas they controlled.

The United Nations says more than 100,000 people have been killed in the Syrian conflict.

Nearly 1.8 million Syrians have fled the country - two-thirds of those since the start of the year - and more than 4.2 million people have been internally displaced, the United Nations has said. Most of those in need are women and children.

Al Jazeera and wire services