Irish police arrested seven people Tuesday suspected of plotting to murder Swedish cartoonist Lars Vilks, who drew a cartoon of the Muslim prophet Mohammed with the body of a dog that was published in a Swedish newspaper in 2007 touching off international furor and formal protest from Iran, Egypt, Afghanistan, Jordan and Pakistan.

Al Qaeda reportedly offered $100,000 to anyone who killed him -- plus a $50,000 bonus if the killer slits his throat.

Ireland's national broadcaster RTE said the suspects are originally from Morocco and Yemen, but are all living legally as refugees in Ireland. The investigation involved authorities in several countries.

Dogs are considered unclean by conservative Muslims, and any depiction of the prophet is strictly forbidden. In 2007 Vilks said his drawing was a calculated move, and he wanted it to elicit a reaction. Vilks, a self-described atheist, points out he's an equal opportunity offender who in the past sketched a depiction of Jesus as a pedophile.