Political cartoonist Zunar is forced to cancel his exhibition featuring 50 pieces of his artworks due to alleged threats from his opponents.

Zunar, whose real name is Zulkiflee Anwar Ulhaque, was supposed to hold the event dubbed "Ketawa Pink Pink" tomorrow on Beach Street, from 8am to 12pm.

"With a heavy heart, I hereby announce the cancellation of my cartoon exhibition in Penang tomorrow because of threats from a group of troublemakers," Zunar said.

"Umno Penang has distributed posters urging their members to come and "visit" my exhibition.

"Based on last year's experience, this is not a normal visit, but more of an act of physical intimidation," Zunar added.

However, Zunar will attend "Defend our Freedom of Expression" forum at the Caring Society, Penang at 8pm tomorrow.

Meanwhile, Zunar claimed that Penang Umno youth under Khairy Jamaluddin has on many occasions become "very rowdy and aggressive".

He recalled his last exhibition in Komtar where a state Umno youth member attacked him, while the police arrested him under the Sedition Act.

The pro-government supporters were upset with his cartoons, which lampoon Prime Minister Najib Abdul Razak and his wife Rosmah Mansor and touches on sensitive issues like the 1MDB scandal.

Just like last year, Zunar said there is no guarantee that the police would take any action to stop them.

"So, I have no choice but to call off the exhibition due to security reasons".

Nevertheless, Zunar said this will not stop him from disseminating messages of anti-corruption through his cartoons.

"Ketawa Pink Pink" (photo) will be turned into another cartoon book very soon, he noted.

"It covers the topic such as 1MDB scandal, the United States Department of Justice exposures and the purchase of hundreds of million of dollars of pink diamonds," he said.

"I am also mooting an idea to make it 'digital open source' - this means that it will be made free for the people to download and distribute the book themselves - providing I get the sponsor for the initial print," Zunar said.

Zunar is banned from travelling abroad since October last year and faces nine charges under the archaic Sedition Act.

Despite the continuous harassment, Zunar received the "Courage in Editorial Cartooning Award” by Cartoonists Right Network International in 2011.

In 2016, he was awarded the "Cartooning For Peace Award 2016" in Geneva.