The United States is offering millions of dollars for the whereabouts of seven key members of the al Qaeda-linked al-Shabaab, a Somalia-based terror group behind bombings and attacks in the region.

The announcement posted on the website of the U.S. State Department's Rewards for Justice program offers $7 million for information on the location of Ahmed Abdi Aw-Mohamed, the founder of al-Shabaab.

In announcing the bounties on Mohamed and his key associates Thursday, the State Department called al-Shabaab "a threat to the stability of East Africa and to the national security interests of the United States."

This year, he and al Qaeda's leader, Ayman al-Zawahiri, released a joint video formally announcing a merger between the terror groups.

The announcement of the bounties follows U.S. strikes that have taken out key al Qaeda leaders, including this week's killing of Abu Yahya al-Libi -- considered the longtime public face of the group.

The battle against al-Shabaab in Somalia

New push against militants in Somalia

Last year, a U.S. drone strike killed Anwar al-Awlaki and al Qaeda founder Osama bin Laden was shot to death by U.S. commandos.

Al-Shabaab, which has battled Somalia's weak transitional government since 2007, controls much of southern Somalia and is active around the capital city of Mogadishu. The U.S. listed it as a terror organization in 2008.

"The group is responsible for the killing of thousands of Somali civilians, Somali peace activists, international aid workers, journalists and African Union peacekeepers," the State Department said.

The State Department is also offering up to $5 million each for information leading to the location of four of Aw-Mohamed's associates, who make up his inner circle: Ibrahim Haji Jama, Fuad Mohamed Khalaf, Bashir Mohamed Mahamoud, and Mukhtar Robow, who acts as the group's spokesman and spiritual leader.

In addition, it is offering up to $3 million each for two of the terror group's other leaders: Zakariya Ismail Ahmed Hersi and Abdullahi Yare.

Al-Shabaab's reach extends beyond Somalia's borders.

It claimed responsibility for 2010 suicide bombings that killed more than 70 people in Uganda and threatened attacks against U.S., Kenyan and Burundian interests in the region.

Mohamed is considered al-Shabaab's operational commander in Somalia and is believed to have been born July 10, 1977, in the Somali city of Hargeisa.

Among Mohamed's inner circle targeted is Jama, described by the State Department as a senior leader. He sometimes uses the alias al-Afghani, which translates as "the Afghan," a nickname he was given because he fought in Afghanistan for several years.

Khalaf is considered the group's leading fundraiser, while Mahamoud is a described as a military commander, according to the Rewards for Justice site.

Hersi, according to the website, is the group's head of intelligence and Yare is the head of its media operations.

The Rewards for Justice program was established in 1984 and has paid some $100 million to more than 70 people for information about terrorists. Rewards go as high as $25 million for information on al Qaeda leader Ayman al-Zawahiri.

The State Department calls the program "one of the most valuable assets the U.S. government has in the fight against international terrorism."