The US government is offering $27m (£18m) in rewards for information on the whereabouts of six leaders of the Somalia-based al-Shabab group.
The highest reward is $6m for the group’s leader Abu Ubaidah.
He replaced Ahmed Abdi Godane, who was killed in a US drone strike last year.
Among those being hunted is Mahad Karate, also known as Abdirahman Mohamed Warsame, believed to be a key player in the attack on a Kenyan university which killed 148 people.
The group, part of al-Qaeda, is battling the UN-backed government in Somalia and has also carried out a string of attacks in neighbouring Kenya.
On Wednesday, Kenyan security forces destroyed five suspected al-Shabab hideouts in the Bono forest close to the Somali border, according to Reuters news agency.
$6m for Abu Ubaidah also known as Direye, named al-Shabab leader in September 2014
$5m for Mahad Karate, also known as Abdirahman Mohamed Warsame, accused of playing key role in Garissa University College attack
$5m for Ma’alim Daud who the US thinks is responsible for al-Shabab’s recruitment and training
$5m for Hassan Afgooye who is believed to oversee the financing of al-Shabab
$3m for Maalim Salman who the US says he has been involved in operations in Africa targeting tourists
$3m for Ahmed Iman Ali who the US believes to have recruited Kenyans
Source: US Department of State
Al-Shabab recruiting in Kenyan towns