Syria has nearly completed surrendering its chemical weapons stockpile, a joint task force in charge of the operation said Thursday, as UN Security Council members called for a fresh probe into alleged gas attacks.

“Today’s operation brings the total of chemical material removed and destroyed to 92.5 percent,” the combined Organisation for the Prohibition of Chemical Weapons-UN task team said in a statement.

Damascus had pledged to have all of its stockpile removed from the war-ravaged country by Sunday. The weapons are then due to be destroyed by June 30.

The consignment of chemicals were delivered to the main Syrian port of Latakia, from where it will be removed by cargo ships for delivery to the US Navy vessel Cape Ray for destruction.

Syrian authorities also “destroyed buildings, equipment and empty mustard gas containers,” the OPCW-UN statement said.

“A majority of (storage and productions) sites are now closed,” the joint mission said.

“I welcome the significant progress of the last three weeks and I strongly encourage the Syrian authorities to conclude removal operations as part of their efforts to achieve the June 30 deadline,” the mission’s chief Sigrid Kaag said.

In New York, Security Council members on Wednesday called for new claims of a chlorine gas attack in a rebel bastion in Syria to be probed after Kaag briefed them behind closed doors.

Joy Ogwu, Nigeria ambassador who holds the rotating presidency, said members “expressed concern about alleged reports about the use of chlorine gas in some of the towns, which left people dead and injured, and called for an investigation into this incident.”

France and the United States allege that President Bashar Assad’s forces may have unleashed industrial chemicals on a rebel-held village in central Hama province earlier this month.

There have been conflicting accounts of the alleged chlorine attack on Kafr Zita, with the government and the opposition trading blame.

Activists have also reported other chlorine gas attacks, most recently in Idlib province, in the northwest, on Monday.

Damascus has denied the attacks.

Under the terms of a US-Russian brokered deal which averted the threat of US military action last year, Syria agreed to destroy its chemical stockpiles.

The deal was reached after deadly chemical attacks outside Damascus last August that reportedly killed hundreds.

The West blamed Assad’s regime but the government said rebels were behind it.