DUBAI -- A group linked to Osama bin Laden's Al-Qaeda network threatened the United States with reprisals after the re-election of President George W. Bush, warning of "unbearable hell," in a website statement on Friday.
"The coming days will show you that the one you preferred will lead you to an unbearable hell," said the group calling itself the Abu Hafs al-Masri Brigades after the Al-Qaeda military chief killed in Afghanistan in October 2001.
In Washington, a US official said the message appeared to be authentic.
He noted that the Abu Hafs Brigades, which has also claimed responsibility for the deadly Madrid train bombings in March, had previously used the website where the latest message was posted.
The bombings killed 191 people in Spain's worst terror attack and injured another 1,900.
"So it appears to be them, given those credentials ... We are taking it seriously and watching it closely," said the official who asked not to be identified.
"Although the criminal Bush has spilt blood of Muslims during the last four years and despite the butcheries that he committed and continues to perpetrate in Afghanistan, in Palestine and in Iraq, we see that... the applause of his people is increasing," the new message said.
"This shows the nature of the American people who approved the war against Islam led by criminal America," it added.
The statement comes after a video message from Al-Qaeda leader Osama Bin Laden -- broadcast just days ahead of the US election -- warned the United States of new attacks similar to those of September 11, 2001 that killed nearly 3,000 people and were claimed by the network.
In the first appearance of bin Laden for over a year, the Al-Qaeda leader accused Bush of "misleading" the American people and of being negligent during the attacks, saying that the "reasons to repeat what happened" still remained.
Bush beat his rival Democrat John Kerry to win a second term in office in Tuesday's vote after a campaign where national security proved a dominant issue.
The new message from the Abu Hafs al-Masri Brigades said it was of no consequence which of the candidates won the election and appeared to threaten new attacks on the United States within the "next days".
"The re-election of the criminal Bush, who is no different from the other leaders of this country who have devoted their efforts to killing Muslims everywhere in the world, will not dissuade the mujahedeen from striking the head of the line of infidelity," it said.
"Bush and Kerry are two sides of the same coin. Both have a dark history that will never be erased. It is the American people who will take the consequences of the politics of its president over the next four years.
"The next days will show that your support of the criminal will not bring you security and will not prevent the muhajedeen from hurting you where you are. The next days will prove this."
In his first pre-election press conference Thursday after his resounding election victory, Bush vowed to "defeat the terrorists and to encourage freedom and democracy as alternatives to tyranny and terror."