• Co-ordinated attacks on neighbouring buildings
• Killers checked in and made bombs in rooms

The menace of international terrorism returned to Indonesia when explosions ripped through two luxury hotels in Jakarta, killing eight guests and injuring at least 50 others.

Two suicide bombers who had checked in as hotel guests triggered the blasts, which occurred within minutes of each other at the neighbouring JW Marriott and Ritz-Carlton hotels in the Indonesian capital’s business district.

Two Australians and a New Zealander were reportedly among the dead, and the wounded included 18 other foreign nationals from the US, Australia, Canada, India, the Netherlands, Norway and South Korea. The Foreign Office said it had no indication of any British casualties.

The attack forced Manchester United, who are on a pre-season tour of south-east Asia, to cancel a friendly fixture against an Indonesian XI in Jakarta on Monday. The team, currently in the Malaysian capital, Kuala Lumpur, had planned to stay at the Ritz-Carlton this weekend.

Investigators say the bombers had checked in to the Marriott on Wednesday and assembled the bombs in a room on the 18th floor, where an unexploded device was found after the blasts. CCTV cameras recorded the moment of the Marriott blast; grainy images show a man pulling a bag on wheels across the lobby before the flash of the explosion.

The bombs went off in the hotels’ restaurants during breakfast. Witnesses reported seeing bloodied bodies being carried away moments after the explosions, which turned the facades of both hotels into masses of twisted metal. Others said they had seen hundreds of guests, most of whom appeared to be westerners, emerge dazed from the Ritz-Carlton as plumes of thick smoke engulfed nearby buildings and restaurants. “There were bodies on the ground, one of them had no stomach,” said a local man.”

The attacks came as Indonesia, the world’s most populous Muslim country, appeared to be re-establishing itself as a tourist destination. They were the first in the country since 2005, when 20 people died in blasts on the resort island of Bali.

No group has claimed responsibility, but analysts believe they were the work of Jemaah Islamiyah, an Islamist militant group that advocates an Islamist super-state spanning Indonesia, Malaysia, the southern Philippines, southern Thailand, Singapore and Brunei. The group carried out a bombing at the Marriott in 2003 in which 13 people died, and is blamed for over 50 other attacks in Indonesia in the last decade. They include the October 2002 bombings of two nightclubs in Bali in which 202 died, mainly westerners.

Indonesia’s president, Susilo Bambang Yudhoyono, condemned the attack as “cruel and inhuman” and vowed to hunt down the perpetrators. Yudhoyono, who was reelected last week, has been credited with bringing peace and stability to a country that had become a target for Islamist militants.”[The bombers] do not have a sense of humanity and do not care about the destruction of our country, because this terror act will have a wide impact on our economy, our business climate, our tourism, our image in the world and many others,” he said.

Australia warned its citizens to reconsider plans to travel to Indonesia, and urged those already there to exercise “extreme caution.” Britons have been advised not to go there unless absolutely necessary.

The Australian prime minister, Kevin Rudd, said he was “sick in the stomach as I think all Australians would feel sick in the stomach. Australians accounted for 88 of the victims in the 2002 attacks on Bali.

“This is an assault on all of us and we are dealing with some very ugly people here,” Rudd said. “Very, very ugly people … and dangerous.”

President Barack Obama said: “These attacks make it clear that extremists remain committed to murdering innocent men, women and children of any faith in all countries.”