The United States is to offer millions of dollars in rewards for information leading to the capture of leaders of the Somali militant group al-Shabab.
It is the first time the US has offered money for specific members of the group, which announced its allegiance to al-Qaeda earlier this year.
It has put a price of $7m (£4.5m) on al-Shabab's founder and commander, Ahmed Abdi aw-Mohamud Godane.
It comes as African Union forces make key advances against the group.
Al-Shabab still controls much of the country but is under pressure from Kenyan, Ugandan and Burundian troops, as well as African Union forces, who have US and European funding.
African Union and Somali government forces last week captured the town of Afmadow, a strategic militant base in the south of the country.
The group released a joint video with al-Qaeda in February, announcing that the two groups had merged.
Appearing on the video, Ahmed Abdi aw-Mohamud Godane, who is also known as Mukhtar Abu Zubair, said he "pledged obedience" to al-Qaeda head Ayman al-Zawahiri, who has a $25m bounty on his head.
The US added al-Shabab to its list of foreign terrorist organisations in 2008. In April, it warned that it continues to receive threats against targets within Kenya.
Under its Rewards for Justice programme, the US is offering money for six other key members of al-Shabab in a total fund of over $30m.
Among those it is seeking is al-Shabab co-founder Ibrahim Haji Jama, and the Swedish Somalian Fuad Mohamed Khalaf, also known as Shongole, who is the group's financier.
Al-Shabab is known to have recruited a number of foreign fighters - many of whom have fought in Iraq and Afghanistan.
Robert Hartung, an assistant director at the US state department's bureau of diplomatic security, said: "Every time we add someone to the Rewards for Justice site, that is a signal that the US government takes the fight against terrorism very seriously."