The UN chemical weapons investigation team continued on Friday its probing mission in Syria and is set to finish their second round of investigation on Monday, according to a statement obtained by Xinhua.

"The United Nations mission investigating the alleged use of chemical weapons in Syria on Friday continued working on a comprehensive report that is expected to be ready by late October, " the statement said.

The UN investigation team returned to Syria on Wednesday to complete their mission.

The fact-finding group was assembled in The Hague in early August.

The team arrived in Syria at the request of the Syrian government on Aug. 18 and inspected some locations in the countryside of the capital Damascus for the use of chemical weapons.

On Aug. 30, the team left to analyze initial findings, after which they affirmed the use of nerve agent, sarin, in the eastern Ghouta suburb of Damascus, which allegedly killed hundreds of people.

However, the rebels and the Syrian government have been trading accusations over the responsibility of the attack.

In its Friday's statement, the team said their report is due to be finalized by late October.

The report will cover the incidents that allegedly took place in Khan al-Assal town in Aleppo, which occurred on March 19, in the Sheikh Maqsoud in the southern province of Daraa on April 13, in Saraqeb in the northwestern province of Idlib on April 29, in the Ghouta suburb of the capital Damascus on Aug. 21, in Bahhariyeh near Damascus on Aug. 22, as well as in Jobar suburb of Damascus on Aug. 24 and Ashrafiah Sahnaya near Damascus on Aug. 25.

Meanwhile, the statement stressed that the team's current activity uses "the same impartial fact-finding modalities and techniques applied to the first round of investigations."

"This means using scientifically agreed and accredited environmental and epidemiological methods such as sampling and laboratory analyses as well as interviews with physicians, victims and parties connected to the incidents," said the team's leader, Professor Ake Sellstrom in the statement.