Forty-four percent of countries have an identifiable risk of terrorist attack, according to Aon P.L.C.'s 10th annual terrorism and political violence map.

The map, published Wednesday in collaboration with London-based Risk Advisory Group P.L.C., shows that the threat of terrorist attacks is particularly prevalent in African countries, especially those in North Africa, Aon said in a statement.

The countries most affected by the threat of terrorism are Afghanistan, India, Iraq, Nigeria, Pakistan, Russia, Somalia, Syria, Thailand and Yemen, according to the map that color-codes risks faced by 200 countries and territories.

The map measures three perils: terrorism and sabotage; strikes, riots, civil commotion and malicious damage to property; and insurrection, revolution, rebellion, mutiny, coup d'etat, war and civil war.

The Middle East is the most unstable region, according to the map, with 64% of countries assigned high or severe risk ratings. The risk of terrorism and sabotage was most prevalent in the Middle East and North Africa, with 85% of countries in that region at risk, according to the research.

This year, the risk ratings were increased for 11 countries that include Argentina, Egypt and Jordan, Aon said. Nineteen countries saw their risk rating downgraded, including Germany, Italy and the United Kingdom.

While the risk level remains low in North America, the recent Boston Marathon bombing highlights the persistent risk of terrorism in the United States while there have been several instances of unrest in Canada, noted Henry Wilkinson, head of the intelligence and analysis practice at Risk Advisory

“Terrorism is having an increasing impact on today's global organizations and terrorist attacks are now regarded as a foreseeable risk,” Neil Henderson, head of Aon Risk Solutions' crisis management team, said in the statement. “An attack not only on, but near, an organization's premises can result in human casualties, property damage, business interruption, legal liability issues, and long-term damage to brand and reputation,” he added.

“The global economic crisis, shifting geopolitical balances and two years of unusually high levels of civil upheaval present challenges and opportunities for businesses looking to expand,” said Mr. Henry Wilkinson,.

The map can be viewed here.