Western embassies received bomb threats yesterday as Indonesia braced itself for the execution by firing squad of the three men who bombed two Bali nightclubs in 2002, killing hundreds of people, most of them foreign tourists.

Security around President Yudhoyono was also tightened after threats to his life were made on the internet.

The US and Australian embassies in the capital, Jakarta, reported finding no bombs after a warning was sent to the Indonesian police.

“I have put TNT bombs around the US and Australian embassies,” the mobile phone text message said. “I will pull the trigger if Amrozi and his friends are executed.”

Security forces were on alert across the country after indications that the three Bali bombers – Amrozi Nurhashyim, Ali Gufron and Imam Samudra – could be executed any day now after the failure of their final appeal last month.

The execution – by rifles aimed at the heart from close range – was expected to be announced early this morning. But the authorities may have decided to avoid potential embarrassment, and any security scares for a VIP guest, the Prince of Wales, who leaves Indonesia tomorrow after a five-day trip.

Armed police and barbed wire were put in place at Cilacap, the port of embarkation for the prison island of Kambangan, where the three bombers are held in a high-security prison. Even relatives of the men were barred from crossing to the island, although they were allowed to pass on gifts of food through prison guards. The head of the prison said yesterday that the three men appeared to be composed and prepared for death. “They’re in good condition, healthy,” Bambang Winahyo told Agence France-Presse. “It seems they’re facing this calmly.”

It was the Indonesian cell of a SouthEast Asian militant group known as Jemaah Islamiyah that planned the three explosions in the resort town of Kuta six years ago, killing 202 people, including 88 Australians, 38 Indonesians and 24 Britons.

Yesterday a few dozen Islamic radicals gathered in the village of Tenggulun in East Java, where Amrozi and his brother Ali Gufron, also known as Mukhlas, grew up. They hung out black flags with religious inscriptions in Arabic and chanted “Free Amrozi! Destroy America!”. “There are hundreds of us waiting to come . . . If Amrozi is executed a thousand more will come,” said one member of the group, Jemaah Ansharut Tauhid, or Partisans of the Oneness of God. “We reject the executions, they are murder,” another activist said. “They were carrying out jihad [holy war] in the way of Islam. Don’t wake the wild, cruel tiger from its sleep!”

A letter posted on a website in Indonesian, Arabic and English urged Islamist militants to “war against and kill” Mr Yudhoyono and other senior officials in retaliation for the executions. “We are taking necessary steps to overcome the threat to the President and officials. This cannot be treated as a mere hoax,” a presidential spokesman told reporters.

None of the three bombers, who were sentenced to death in 2003, has expressed any regret for the attack, except to say that they were sorry that there were Muslim victims. Imam Samudra, known as the “smiling bomber” said this month: “I don’t ask for forgiveness from infidels. I only ask for forgiveness from Muslims.”

The Australian Government has advised its citizens to “reconsider your need to travel to Indonesia, including Bali, at this time due to the very high threat of terrorist attack”. The British Foreign and Commonwealth Office merely advised caution. “As elsewhere in Indonesia you should avoid any demonstrations or large gatherings of people,” its travel advice for Indonesia reads. “If you become aware of any nearby violence you should leave the area immediately.”

Times Recommends

• Michael Jackson: Not the final chapter
• Indian Army spends10m rupees on golf buggies
• Brüno toned down for 15 rating