Manhunt Underway for Tunisia Massacre Suspects

Tunisian authorities have launched a nationwide manhunt for any accomplices in Friday's beach massacre, and British authorities are joining in the investigation.

The suspect in that terror attack slaughtered at least 38 people as they were vacationing at the Imperial Marhaba Hotel in the beach resort of Sousse.

Because many of the victims were British, 600 British counterterrorism police have been deployed as part of the investigation into Friday's attack. Britain is also taking steps to monitor the online efforts of jihadists at home.

"We've seen the nature of the threat changing. More and more use of social media, more and more passive messaging to potential jihadists, and very, very little way of knowing which ones will respond to a particular provocation, a particular message," British Foreign Secretary Philip Hammond said.

Hammond said officials can't be 100 percent successful at stopping lone wolf terror attacks, but they're doing everything they can to monitor threats on social media.

"It is the most difficult type of attack to detect and predict and therefore the most difficult kind to protect against," he explained.

Radicalization of the youth is a problem across North Africa, but especially acute in Tunisia. Some 3,000 of its citizens have left to join extremist groups in Syria, Iraq, and Libya, and at least 500 are believed to have returned, battle-hardened, to spread radical ideologies back home.

Friday's incident is the worst terror attack in Tunisia's history. In March, terrorists massacred 22 people, mostly tourists, at the Bardo National Museum in Tunis.

The two attacks have called into question the newly elected government's ability to protect the country.

Tunisia is the only democracy that emerged from the turmoil of the so-called Arab Spring of 2011. It's a country full of vulnerable targets, with an economy that depends on welcoming European tourists to its warm Mediterranean shore.