(CNN) A new law which comes into effect from next week will punish homosexual sex and adultery with death in the small southeast Asian kingdom of Brunei.

Beginning on April 3, any individuals found guilty of the offenses will be stoned to death, according to a new penal code. The punishment will be "witnessed by a group of Muslims."

The country's strict new laws were announced in 2014, and have been rolled out gradually. The latest phase of implementation, including the brutal new provisions, was quietly announced on the Brunei attorney general's website on December 29, 2018.

Human rights groups were quick to express horror at the penal code, which will also order amputation as a punishment for theft.

"Brunei must immediately halt its plans to implement these vicious punishments, and revise its Penal Code in compliance with its human rights obligations. The international community must urgently condemn Brunei's move to put these cruel penalties into practice," Rachel Chhoa-Howard, Brunei Researcher at Amnesty International, said in a statement.

System based on religious and common law

There was a broad international outcry when in 2014 Brunei became the first country in the region to adopt Sharia law, an Islamic legal system which outlines strict corporal punishments.

With more international pressure, the small nation said it has no plans to halt the law.

A new statement from the office of Brunei's Prime Minister says the country has "always been practicing a dual legal system, one that is based on the Syariah (Shariah) Law and the other on Common Law."

The two systems will run in parallel starting April 3, the statement said, and will "maintain peace and order and preserve religion, life, family and individuals regardless of gender, nationality, race and faith."

"The Syariah Law, apart from criminalizing and deterring acts that are against the teachings of Islam, it also aims to educate, respect and protect the legitimate rights of all individuals, society or nationality of any faiths and race."

The tiny, oil-rich kingdom of just over 450,000 people is located on the island of Borneo, close to moderate Islamic nations of Indonesia and Malaysia.

In comparison to its neighbors, Brunei has grown conservative in recent years, including banning the sale of alcohol.

The new penal code was announced in May 2014, by the Sultan of Brunei, Hassanal Bolkiah, who also acts as the country's prime minister. In announcing the change, government's website quoted the Sultan saying that his government "does not expect other people to accept and agree with it, but that it would suffice if they just respect the nation in the same way that it also respects them."

International pushback

On March 28, George Clooney called for a boycott of the nine hotels linked to Brunei -- three of which are in the UK, two in the US, two in France and two in Italy.

They include the Beverly Hills Hotel and the Bel-Air in Los Angeles, the Dorchester in London and Le Meurice in Paris.

"Are we really going to help pay for these human rights violations? Are we really going to help fund the murder of innocent citizens?" he wrote.

Other world leaders have followed in denouncing the country's harsh practices and stood by the LGBT community.

Austrian Chancellor Sebastian Kurz called the decision "cruel and inhumane."

He said on Twitter: "I call on the Sultanate of Brunei to withdraw the death penalty by stoning f homosexual acts between consenting adults. The same goes for other countries which have the same cruel & inhuman laws. No one should be criminalized based on their sexual orientation or gender identity."

The UK's Secretary of State for International Development Penny Mordaunt said "No one should face the death penalty because of who they love. Brunei's decision is barbaric and the UK stands with the LGBT+ community and those who defend their rights. LGBT+ rights are human rights."

And Former Vice President Joe Biden commented on the new law saying it was "appalling and immoral."

"Every single person on earth is entitled to be treated with dignity and to live without fear," he said on Twitter. "There is no excuse -- not culture, not tradition -- for this kind of hate and inhumanity."