The United Nations has declared a cease-fire in Yemen in an attempt to stem violence in a conflict that has left thousands dead over two years of fighting.A coalition of countries led by Saudi Arabia has been carrying out airstrikes against Houthi groups in Yemen since March of 2015. The U.S.-backed coalition supports the government of Abd Rabbu Mansour al-Hadi, who was ousted when Houthi rebel groups took over the capital city of Sana’a in 2014.Violence has been increasing in Yemen since an attempt at peace talks failed in August. Last week, an airstrike by the Saudi-led group killed 140 people at a funeral gathering, prompting international outrage and calls for change.Saudi Foreign Minister Abel al-Jubeir told reporters Monday that he is prepared to support a cease-fire if the Houthi groups also agree.