According to CNN on Monday, a team of inspectors were met with gunfire and an explosion in Damascus.
Bullets hit one of the vehicles, but no one was injured.
Inspectors were promised by the Syrian government that both battling sides in the area would leave the site clear of violence.
"The first vehicle of the Chemical Weapons Investigation Team was deliberately shot at multiple times by unidentified snipers in the buffer zone area," a U.N. statement said according to Reuters.
President Bashar al-Assad’s government blamed terrorists for the attack in the buffer zone where the inspectors were stationed.
The UN and other world leaders speculated on whom is responsible for a deadly chemical attack that killed hundreds of people, including young children, in Damascus earlier in August.
Several countries speculate that Assad’s regime is responsible for the attack, but the Syrian government has publicly denied the allegations.
The team said that the week it has taken to enter the area could be detrimental due to the fact that whoever was responsible may have destroyed evidence.
"Every hour counts. We cannot afford any more delays. We have all seen the horrifying images on our television screens and through social media,” U.N. chief Ban Ki-moon said in the report.
U.S. President Barack Obama declared the attack a “red line” that could result in action by international forces if it is proven that the Syrian government attacked its own citizens.