The Danish artist whose controversial cartoon of the Prophet Muhammad enraged Muslims around the world said Monday that police cannot protect him from attackers who act spontaneously.

Kurt Westergaard said in an interview with The Associated Press that he believes he is being targeted by Muslim extremists because he stands by his cartoon and insists he has "not done anything wrong."

The 74-year-old artist said he was shocked by Friday's attack during which a Somali man broke into his home armed with an ax.

Police shot the Somali man in the hand and knee, and he was later charged with attempted murder. The man cannot be identified due to a Danish court ban.

Westergaard said police cannot protect him 100 percent from "the terrorist type" who acts spontaneously and is "not part of a conspiracy."

Westergaard's drawing of the Prophet Muhammad wearing a bomb-shaped turban was printed in the Jyllands-Posten newspaper in September 2005. The daily had asked Danish cartoonists to draw Muhammad as a challenge to a perceived self-censorship. In early 2006, Danish and other Western embassies in several Muslim countries were torched by angry protesters who felt the cartoons had profoundly insulted Islam.

"I have not done anything wrong," Westergaard said by telephone on Monday from an undisclosed house where he was kept under police protection. "To me, it was just another day at the office."

Islamic law generally opposes any depiction of the prophet, even favorable, for fear it could lead to idolatry.

In an unrelated development, a Swedish artist who depicted Prophet Muhammad as a dog in a Swedish newspaper in 2007 said he received a telephone threat on Monday. Lars Vilks said an unidentified man with a Swedish accent claimed he was calling from Somalia to tell the artist "he was next in line" after Westergaard.

Police confirmed that Vilks has reported the threat to them, but said it has not been investigated yet.

Westergaard remains a potential target for extremists because his cartoon is viewed as the most provocative of the depictions of Muhammad that 11 other Danish artists had printed in the Jyllands-Posten newspaper.

"Maybe because I am the one who feels the best about standing forward and speaking about what I have done, I stand by my drawing," Westergaard said.

Friday was not the first time the bearded Dane has generated plots against him.

In October, terrorism charges were brought against two Chicago men who allegedly planned to kill him and a newspaper's former cultural editor. That trial has not yet begun.