美国有线新闻 CNN 美国称军舰遭胡塞武装导弹袭击 回顾伊斯兰教派之争（在线收听）

Jumping right in, a U.S. warship was recently targeted by two missiles near the Middle Eastern country of Yemen. A military spokesman said the USS Mason was in international waters in the southern part of the Red Sea when the attack happened. The ship deployed onboard defensive measures. The missiles missed their apparent target, hit the water, caused no damage.

But where they did come from? The U.S. says they were launched from a part of Yemen controlled by Houthi rebels. Who are the Houthis? They're a group thatdrove outthe Yemeni president and government last year. The Houthis have taken control of much of war-torn Yemen, but they deny that they targeted the U.S. warship.

This goes deeper though. The Houthis are Shia Muslim group and they're supported by Iran, a mostly Shia Muslim country. But they're opposed by Saudi Arabia, a mostly Sunni Muslim country that's leading other nations in attacks against the Houthis.

Tensions between Shia and Sunni Muslimsdate backcenturies.

SUBTITLE: Sunni vs. Shia Islam.

NIC ROBERTSON, CNN INTERNATIONAL DIPLOMATIC EDITOR:When Islam's founder, the Prophet Muhammad died in the seventh century, his followers were split over who shouldtake over, Abu Bakr was one follower. They wanted to choose. Others wanted his cousin and son in law, Ali.

Ali became the leader for all Muslims for five years before he was killed. His son Husayn was killed in battle by what were to become the Sunnis.

Since then, the followers of Ali have been known as Shia.

Across the world, the vast majority of Muslims are Sunnis. What makes the Middle East so complicated are the maps that were drawn and the national boundaries that were put down about a century ago when British and the empires werepulling backfrom the region and the struggle for power today has its roots in how the region was divided, how those maps were drawn.