On March 29 the RCMP arrested a man on terrorism related charges as he was about to board a plane in Toronto. The RCMP said he was enroute to Somalia, where he intended to join al-Shabaab, a Somali insurgent group with links to al-Qaeda.

On March 7, 2010, the Canadian government added al-Shabaab to this country's terrorist list, following claims that the organization is targeting Canadian youth. The designation came a week after the British government did the same thing.

What is al-Shabaab?

The al-Shabaab Mujahedeen is an armed group of mostly young adherents in Somalia with links to al-Qaeda. Shabaab means youth in Arabic.

The group currently controls large swaths of southern Somalia, including parts of the capital, Mogadishu.

The Stratfor intelligence company puts the number of al-Shabaab fighters at 6,000-7,000.

When was the group formed?

In 2006, a loosely affiliated group known as the Islamic Courts Union, composed of Sharia court officials and other Islamists, took control of much of southern Somalia, including Mogadishu, from the Transitional Federal Government.

Somalia President Sheikh Sharif Ahmed, a former insurgent, has asked for Western help in combatting the two main Islamist groups, including al-Shabaab. Reuters

In July, neighbouring Ethiopia, with U.S. backing, invaded Somalia and defeated the ICU forces by the end of 2006.

The defeat led to the splintering of the ICU coalition and al-Shabaab was one of two prominent hard-line groups that emerged from the ICU as a separate organization.

At the time, Osama bin Laden and other al-Qaeda leaders were issuing statements about Somalia, including calls for foreign Islamists to go there and fight.

What relationship is there between al-Qaeda and al-Shabaab?

In an interview with The Los Angeles Times in 2008, Sheik Muktar Robow, an al-Shabaab leader and spokesman, said the group was negotiating with al-Qaeda to "unite into one."

He said al-Shabaab would take orders from bin Laden and that, "al-Qaeda is the mother of the holy war in Somalia."

Robow went on to say that "most of our leaders were trained in al-Qaeda camps. We get our tactics and guidelines from them. Many have spent time with Osama bin Laden."

Nevertheless, in February 2010, the BBC claimed that al-Shabaab had just, "confirmed for the first time that its fighters are aligned with al-Qaeda's global militant campaign."

The story was picked up by many other news organizations.

What does al-Shabaab want?

According to a statement released in December 2007, al-Shabaab is:

"Seeking to establish an Islamic state along the lines of the Taliban-ruled, by-the-law-of-Allah in the land of Somalia; regards the rulers of the Muslim world today as branches of the international conspiracy against Islam, and thus they are to be regarded as infidels and overthrown; [and] seeks to expand the jihad to Somalia's Christian neighbours, with the intent of driving the infidels out of the Horn of Africa, along the same lines as al-Qaeda has been striving to do under the slogan, 'expelling the infidels out of the Arabian Peninsula.'"

Who are the leaders?

The movement's founder was Aden Hashi Ayro who was killed in a U.S. air strike on May 1, 2008.

In the obituary for their fallen leader, al-Shabaab said that the 1993 battle for Mogadishu was, "the first time he fought under the supervision of al-Qaeda."

Ayro went on to become a top leader of the Islamic Courts Union, along with Sheik Sharif Sheik Ahmed, the former insurgent who is currently the president of Somalia, supported by the U.S. government.

Al-Shabaab's current leader, Ibrahim 'al-Afghani,' replaced Sheikh Mukhtar Abu az-Zubair in December 2010 after an internal power stuggle. Both men were born in Somaliland.

Omar Hammami, also known by his nom de guerre "the American," one of al-Shabaab's rising operatives. (From an al-Shabaab video on YouTube)

Rising in the ranks is Omar Hammami (a.k.a. Abu Mansoor Al-Amriki, "the American"). He was born in Alabama and, according to news reports, baptized in a Southern Baptist church.

Hammami moved to Toronto in 2004 and married a Somali-Canadian woman during the year he lived in the city.

For at least the past four years he has been in Somalia with al-Shabaab, playing a prominent role in their recruitment campaign.

On March 8 Somalia's defence minister claimed that Hammami had been killed but offered no evidence. U.S. intelligence officials disputed the report.

How does the West feel about al-Shabaab?

Al-Shabaab is classified as a terrorist organization in Canada, the U.S., the U.K., Australia, Sweden and Norway.

In 2009, CBC News reported federal government suspicions that al-Shabaab may have recruited as many as 30 Somali-Canadians. In 2011 officials said they considered the group the top threat to Canada's national security.

Mohamed Abdullahi Mohamed, a Somali-Canadian who quit al-Shabaab in 2009, said on the CBC program Connect that his nightmare now is that a young man recruited in Canada and trained in Somalia will return "here to carry out a suicide attack."

U.S. authorities believe about 20 Somalis from the U.S. have joined al-Shabaab. In summer, 2010, four Americans were arrested for attempting to join al-Shabaab.

Is there any relationship between al-Shabaab and Somali pirates?

"There is no overt relationship between al-Shabaab and pirate gangs," according to the author of the 2009 book, Terror on the Seas: True Tales of Modern Day Pirates.

In an interview with CBC News, Canadian Daniel Sekulich went on to say that despite "diametrically opposed goals, there is suspicion that al-Shabaab may be allowing pirates to operate from their territory in order to gain some income."

Terrorism expert Evan Kohlmann, from the NEFA Foundation, notes that al-Shabaab is "a movement which is cash-hungry and can recognize valuable pragmatic opportunities when they exist."