17.40 GMT: It would appear the immediate threat from more terrorist threats is over, although the States has gone into a state of panic. Hundreds of buildings across the US, viewed as possible targets, have been evacuated. All airports have been shut down. Borders shut. The flood of calls into New York has jammed switchboards. Companies are setting staff home early.
One person put the World Trade Center up for sale on eBay but the sick joke was removed almost immediately. News Web sites have started popping back up as the initial demand lifts and the blame seems to have fallen on notorious terrorist Usama Bin Laden.
The number of dead and injured remain impossible to predict except that they will probably be in the thousands. Press conferences are due to take place in the next few hours.
16.37PM GMT Thousands of people are feared dead following suicide plane-crash attacks on the World Trade Center, in New York today.
Twenty-five thousand people were thought to be working in the twin towers of World Trade Center in New York at the time of the kamikaze assaults. Both of the 110-storey towers collapsed within two hours of the onslaught.
A third plane has crashed into the Pentagon, Washington, part of which has collapsed, and a fourth plane has crashed south east of Pittsburgh. A fifth plane is reported to be heading towards Washington DC, according to Sky News.
American Airlines has confirmed that it has lost two planes with a total of 156 people on board, one from Boston and one from Washington DC.
Up to eight airplanes are said to have been hijacked,
US air authorities say that three planes are unaccounted for.
Yasser Arafat has condemned the attacks, but current speculation still puts the blame on Palestianian separatists. All Israeli embassies in the US have been evacuated as has the UK stock exchange. Part of the Pentagon has also collapsed. All civilian planes in the US are grounded.
The incredible spate of terrorist attacks has knocked most the world's news sites off the Internet as people tried to find out the latest news.
CNN has been offline ever since the news that a second plane had crashed into the World trade Center. The BBC has fared little better, which the site now inaccessible. MSNBC was available for a short while but seems to have disappeared as well following the posting of a video of the second plane crashing.
[16.50PM GMT: Most news sites have now put up a simple front page with a list of stories in order to bring themselves back online]
The news that a bomb has gone off just outside the Pentagon and a third explosion near the World Trade Center have only added to the problems. All UK newspaper sites are struggling with demand, working at an incredibly slow rate. Only The Guardian and the FT are offering accessible information as we write.
The World Trade Centre Association Web site has also vanished, and access to any New York Webcams is impossible. Tony Blair has cancelled his speech at the TUC to fly back to London.
The only news sites that seem to have weathered the demand so far are the Press Association's Ananova site and Sky TV's Sky.com, although that too is having trouble now. Ananova reckons eight planes in total have been hijacked. All planes in US airspace have been ordered to land as soon as possible.
It seems that the Internet has failed in its first truly hard test as a news disseminator. The best coverage is coming from the usual TV outlets.
More as things go on. ®