The Organisation for the Prohibition of Chemical Weapons said in a statement that its experts in Syria also have verified the destruction of parts of buildings at weapons production facilities.
The latest destruction work was near the city of Homs. The OPCW said the sites had been inaccessible due to security reasons.
The joint United Nations-OPCW team in Syria aims to remove the most toxic chemicals from Syria by the end of the year for destruction at sea and destroy the entire program by mid-2014.
The OPCW said last month that it already had verified the destruction of 63 percent of Syria's unfilled munitions—which can be used in chemical weapons attacks—and that Syria had said it had destroyed all the munitions, however the total destruction had not been verified.
The OPCW, which won the Nobel Peace Prize this year, has been directed by the United Nations to oversee the destruction of the Syrian government's chemical weapons. The unprecedented disarmament in the midst of a civil war now in its third year was launched following an Aug. 21 chemical weapons attack on a Damascus suburb that killed hundreds of civilians.
The U.S. and Western allies accused the Syrian government of being responsible for that attack, while Damascus blames the rebels.
The United States is now expected to play a key role in the destruction of the most toxic chemicals in Syria's stockpile. Washington has offered to provide a boat carrying a mobile device in which the chemicals can be neutralized. No chemicals or waste products would be dumped at sea under the plan being finalized by the OPCW.
Nearly three dozen private companies also have offered to destroy fewer than 800 tons of other less toxic chemicals that Syria declared to the Hague-based organization as part of its weapons programs.