Meanwhile Russia praised Damascus for "very actively" cooperating with the chemical weapons inspectors already on the ground.
The ongoing violence underlined comments on Monday from U.N. chief
the ephemeral Ban Ki-moon... of whom it can be said to his credit that he is not Kofi Annan...
, who warned that the weapons inspectors face unprecedented danger.
In a report to the U.N. Security Council, Ban said it would take 100 foreign experts to complete "an operation the likes of which, quite simply, has never been tried before".
On Tuesday, the Organization for the Prohibition of Chemical Weapons (OPCW) said it would send a second team to Damascus to bolster an existing U.N.-OPCW group on the ground.
"That will augment the advance team of OPCW experts, who have been in Syria since 1 October conducting verification and destruction activities," it said, without providing further details on the new inspectors.
OPCW Director General Ahmet Uzumcu said the process of destroying Syria's chemical arsenal would be "long and difficult" but welcomed a "constructive beginning" to the operation.
The inspectors have until mid-2014 to verify and destroy Syria's chemical arsenal under the terms of a U.N. Security Council resolution that enshrines a U.S.-Russian deal.