CNN launches the new weekend series “Special Investigations Unit” (7 p.m. today and Sunday, CNN). The program will not feature a single host, but employ the network’s stable of journalists, including Christiane Amanpour, anchors Anderson Cooper and Soledad O’Brien, chief medical correspondent Dr. Sanjay Gupta, correspondents John Roberts, John King, Candy Crowley, Drew Griffin and others to offer hourlong, in-depth reports in areas pertinent to their expertise.

“Unit” kicks off with Amanpour’s report “The War Within,” a look at the growing problem of extremism in Britain’s Muslim communities.

Muslims came under increased scrutiny after the suicide bombings in the London subways. Amanpour interviews radical clerics, community leaders, a female Muslim standup comic, a punk-music producer and a graffiti artist to get a range of opinions.

A fiery self-appointed mullah uses the Koran to extol holy war. But a young Muslim condemns his vengeful ideology as a form of “mental illness.” Almost everyone agrees that the war in Iraq and the overall war on terror have made Muslims feel isolated and under suspicion. Some cope with this better than others. The comic says her brother has been taunted continually, but when strangers accost him with the insult “Bin Laden,” he replies, “No, I’ve been shopping!”

According to this report, most of the youths courted by extremists are native-born Britons. They’re soccer fans with East End accents. And while some of their disaffection and anger are fueled by foreign policy, they also stem from generational issues. The mullahs and mosque leaders tend to be old men who adhere to the tribal traditions of their native Pakistan. They resent the teenagers’ impertinence and often throw them out of their mosques. This makes the young people easier prey for jihad-preaching mullahs who infuse holy war and even suicide bombing with the cool cachet of youthful rebellion.

¢ The documentary “Ocean’s Deadliest” (7 p.m. Sunday, Animal Planet) looks at some of the venomous sharks, snakes and salt-water crocodiles lurking just off the coast of Australia. This film was also the final documentary made with naturalist Steve Irwin, who was killed during its production. “Deadliest” also looks back at Irwin’s life and work.

Tonight’s highlights

¢ Scheduled on “Dateline” (7 p.m., NBC): how a subway killer evaded justice.

¢ Secret agents, hidden clues and sudden heists abound in the new cartoon series “The Secret Show” (7:30 p.m., Nicktoons)

¢ A corpse in Central Park reveals scenes from a marriage on “Law & Order: Special Victims Unit” (9 p.m., NBC).

Sunday’s highlights

¢ The New England Patriots meet the Indianapolis Colts in the AFC championship game (6 p.m., CBS).

¢ Auditions continue on “Grease: You’re The One That I Want” (7 p.m., NBC).

¢ “Explorer: Iraq’s Guns for Hire” (8 p.m., National Geographic) looks at the men who work as private-security contractors in the war zone’s deadliest districts.