Anwar al Awlaki, US-born Yemeni cleric, targeted by drone (VIDEO)

A U.S. drone attack in Yemen Thursday targeted but failed to hit a U.S.-born radical Yemeni cleric, Anwar al Awlaki.

The missile attack on a car did kill two brothers thought to be mid-level Al Qaeda militants, Reuters reports.

Awlaki has been accused of encouraging attacks on the United States and is considered the leader of Al Qaeda in the Arabian Peninsula. He is one of the worlds most wanted terrorists.

"We were hoping it was him," a U.S. official told CBS News.

The intended drone attack on one of Al Qaeda's influential leaders comes less than a week after U.S. forces killed the leader of Al Qaeda, Osama bin Laden.

The attempt to kill Awlaki is the first known U.S. drone attack inside Yemen since May 2010, when a missile accidentally killed one of the president's envoys, BBC reports.

Al Qaeda in the Arabian Peninsula has about 300 members and is thought to be behind attacks on government targets, states Reuters.

The Wall Street Journal reports that the group is considered the world's most active terrorist organization.

Awlaki has been linked to three major terror incidents: the Fort Hood shootings, the Christmas 2009 airplane plot and a plan to blow up cargo planes.

The United States has been working closely with Yemen to investigate and find terror suspects. Yemeni President Ali Abdullah Saleh has increased his cooperation as he has faced major protests at home in an effort to gain U.S. support, a U.S. official told the Wall Street Journal.