Several rings of checkpoints were set up around the May 22 Stadium in the southern port of Aden, the host city for the eight-nation event, and police earlier stopped a protest rally called by southern separatists.
In the opening match, Saudi Arabia beat Yemen 4-0. Kuwait and Qatar were playing later Monday.
The event’s opening ceremony featured an artistic display by about 1,500 dancers from Yemen and other Gulf countries that reflected the region’s history and cultural life.
The tournament draw in August had prompted leaders of a separatist movement in southern Yemen to demand that the UAE, Bahrain, Saudi Arabia, Oman, Qatar, Kuwait and Iraq boycott the competition.
There are also almost daily clashes between the military and suspected Al-Qaeda gunmen. Yemen, the poorest country in the Arab world, is reported to be a hideout for hundreds of militants from Saudi Arabia and Yemen who united early in 2009 to form Al-Qaeda in the Arabian Peninsula.
The first goal of the tournament came from a header by Saudi Arabia’s Osama Al-Mawled in the third minute.
Mohammed Al-Shalhoub doubled his side’s lead in the 57th minute and Muhannad Asiri netted the third in the 70th minute from a penalty kick. Yemeni defender Basil Al-Aqel was sent off one minuter later.