HAVANA - Cuba is mobilizing international help to urge the return of four Cubans who were arrested in the US 15 years ago.

For that purpose, the Cuban Institute of Friendship with Peoples (ICAP) said Wednesday it will hold a forum on September 12, the 15th anniversary of the arrest.

The event was called as the International Colloquium for the Release of The Cuban Five, including Gerardo Hernandez, Antonio Guerrero, Fernando Gonzalez, Ramon Labanino and Rene Gonzalez, who were convicted in US of spying and other crimes June 2, 2001 and sentenced to jail terms ranging from 13 years to two life terms plus 15 years.

Rene, who was born in Chicago, was granted conditional release in 2011 and allowed last April to attend his father's funeral in Havana.

Rene petitioned to renounce his US citizenship in exchange for remaining in Cuba with his family, a request that was permitted by a local Florida judge in May.

Cuba has admitted the men were monitoring the activities of Cuban extreme right-wing organizations in the US, which were plotting to overthrow the Cuban government, but maintains they were not involved in espionage against the US and do not deserve lengthy prison sentences.