UPDATE 1-UN to launch probe of alleged Syria chemical arms attack

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UNITED NATIONS, March 21 (Reuters) - U.N. Secretary-General Ban Ki-moon on Thursday announced that the United Nations will launch an investigation as requested by the Syrian government into allegations that chemical weapons were used in Syria.

"I have decided to conduct a United Nations investigation into the possible use of chemical weapons in Syria," Ban told reporters. He said the investigation will focus on "the specific incident brought to my attention by the Syrian government."

Syria asked Ban on Wednesday to investigate an alleged chemical weapons attack by "terrorist groups" near the northern city of Aleppo on Tuesday, Syrian U.N. Ambassador Bashar Ja'afari said.

The Syrian opposition said on Wednesday that there was a second chemical weapons attack on Tuesday in Damascus in addition to the one the government and opposition accuse each other of carrying out in Aleppo on the same day.

But Ban made clear that the focus of the investigation he announced would be the Aleppo attack.

"I am of course aware that there are other allegations of similar cases involving the reported use of chemical weapons," he said, adding that the United Nations would be cooperating with the Organisation for the Prohibition of Chemical Weapons (OPCW) and the World Health Organisation (WHO).

"Full cooperation from all parties will be essential. I stress that this includes unfettered access," he said. "I reiterated this point in my communications with the Syrian authorities."

"There is much work to do and this will not happen overnight, it is obviously a difficult mission," Ban said. "I intend for this investigation to start as soon as is practically possible."

(Reporting By Michelle Nichols; Writing by Louis Charbonneau; Editing by Vicki Allen)

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Keywords: SYRIA CRISIS/CHEMICAL UN