Kenyan police have named three men it believes to be the major recruiters of young Kenyans to Islamist terror groups, especially Somalia's al-Shabab.
All three were operating in Kenya but are now based in Somalia, the police report said.
One is believed to have helped plan the 2013 Westgate shopping centre attack in Nairobi, the other two are clerics.
The report said young Kenyans from around the country were being targeted without the knowledge of their parents.
The Kenyan police report, "Tracing the disappearing Kenyan youth", named the three key recruiters as:
- Abdifatah Abubakar Ahmed - al-Shabab commander and planner of the Westgate attack, co-ordinates recruitment in Kenya's coastal region, including young women as wives for fighters in Somalia. Held fraudulent Kenyan ID, deported to Somalia in 2008
- Ramadhan Hamisi Kufungwa - once imam in charge at Musa Mosque in Mombasa. Continues to facilitate movement of recruits to Somalia
- Ahmed Iman Ali - studied engineering at University of Nairobi, preached at a mosque in Nairobi's Majengo area, appears in al-Shabab propaganda videos. Went to Somalia in 2009.
It said most of their recruits went to Somalia for training and came back to take part in attacks in Kenya.
Recently, Islamic State had also become an "attractive group" to "vulnerable Kenyans", the report said.
More on al-Shabab in Kenya:
Some Muslim clerics especially in the port city of Mombasa have been accused of having links with al-Shabab.
A prominent cleric Abubaker Shariff Ahmed, known as Makaburi, was assassinated last year.
He was named in a UN Security Council report as "a leading facilitator and al-Shabab recruiter" in Kenya.
Some Muslims and human rights groups have accused the Kenyan police of killing clerics suspected of having link with Islamist groups.
The police have vehemently rejected the allegations.