(CNN) -- A team of U.N. chemical weapons inspectors are in Syria where they will begin an investigation Monday into whether chemical weapons have been used during the bloody civil war there.
The team won't be speaking to reporters during the visit, it said in a written statement, U.N. Secretary-General Ban Ki-moon's office said.
Syria has been embroiled in a war for more than two years, during which more than 100,000 people have been killed and millions have been displaced or become refugees in other countries, according to the United Nations.
Amid the fighting, there have been numerous allegations that chemical weapons have been used.
In June, the White House said Syrian President Bashar al-Assad's forces had crossed a "red line" by using chemical weapons, including the nerve agent sarin gas, against rebel forces. This prompted the U.S. government to begin providing military support to opposition fighters, despite its earlier reluctance to do so.
Syria's government, meanwhile, has claimed rebel fighters have used chemical weapons as well. That includes a March incident in Khan al-Asal in the northern province of Aleppo, according to state media.
Opposition officials have said rebels don't have access to chemical weapons or the missiles needed to use them in an attack, while other rebel leaders said Syrian troops fired "chemical rockets" at civilians and opposition forces.
The government has agreed to arrangements "essential for cooperation to ensure the proper, safe and efficient conduct of the mission," the secretary-general's office said last week. Khan al-Asal will be one of the three incidents that U.N. inspectors will look into, a U.N. spokesperson said in late July.