DAMASCUS, Syria — Snipers opened fire today at a U.N. vehicle belonging to a team investigating the alleged use of chemical weapons in Damascus, a U.N. spokesman said. The Syrian government accused the rebels of firing at the team.

Activists said later that the team had arrived in Moadamiyeh, a western suburb of the capital and one of the areas where the alleged attack occurred. They said the team was meeting with doctors and victims at a makeshift hospital.

Martin Nesirky, spokesman for U.N. Secretary-General Ban Ki-moon, said the vehicle was “deliberately shot at multiple times” in the buffer zone area between rebel- and government-controlled territory, adding that the team was safe.

News of the sniper attack came only a few hours after the team members wearing body armor left their hotel in Damascus in seven SUVs, headed to the site of the alleged attack.

Nearly an hour before the team left, several mortar shells fell about 700 yards from their hotel, wounding three people. One of the shells struck a mosque and damaged its minaret.

World leaders have suggested that an international response to the attack was likely.

The United States has said that there is little doubt that Assad's regime was responsible for the attack on Aug. 21 in the capital's eastern suburbs. The group Doctors Without Borders said 355 people were killed in the artillery barrage by regime forces that included the use of toxic gas.