Suspected al-Qa'ida bomb attacks foiled in UK and Dubai

A suspected al-Qa'ida terror attack was foiled yesterday after two bombs posted to the United States were uncovered in Britain and Dubai.

The US President, Barack Obama, described the plot as a "credible terrorist threat against our country" which had its origins in Yemen where several al-Qa'ida cells are known to operate.

The packages, which contained printer cartridges with wires attached, were addressed to Jewish organisations in Chicago, and were on Chicago-bound cargo planes that had set off from Yemen in the Middle East.

Also yesterday, a commercial passenger jet carrying cargo from Yemen landed in New York under military fighter jet escort, and passengers on a British Airways passenger flight from London to New York were kept on board on arrival while security staff checked cargo items "one by one". British Airways said all passengers on board the flight at JFK had disembarked safely

Theresa May, the Home Secretary, was last night reviewing security measures for cargo bound for Britain that originates in Yemen. The plot was considered serious enough that Cobra, the Government emergency committee, was convened to discuss developments and consider how to respond. Mrs May later briefed the US Department of Homeland Security Secretary Janet Napolitano.

"Safety and security of the UK remains my number one priority. We are working closely with our international colleagues and will continue to do so," she said. "At this stage there is nothing to suggest that any location in the UK was being targeted. We are urgently considering what steps need to be put in place regarding security of freight originating from Yemen. For security reasons there are currently no direct flights from Yemen to the UK."

An international hunt for bombs was launched after an intelligence tip-off in Britain led to a search at East Midlands Airport of cargo that originated from Yemen.

The package arrived in Britain on an American-registered cargo plane from the Yemen that made a routine stop at the East Midlands Airport. The device was well hidden and was only uncovered when a second search was ordered after the first drew a blank. The device was said to include wires and white powder in a toner cartridge but there were suggestions the explosives may have been found in a second suspect package.

Another explosive device was discovered in Dubai. It had been sent from Yemen using FedEx, and the company last night suspended all shipments from Dubai, where its regional hub is based. UPS similarly suspended its cargo services out of Yemen.

Two UPS flights to the US were also searched and a third flight, an Emirates passenger service from Dubai, was given a fighter escort as it crossed the Canadian border. Investigators believe the explosive used was pentaerythritol trinitrate (PETN), the same type that was used in the botched Christmas Day bomb plot that has already been linked to Yemen. It was also used by Richard Reid, the shoe bomber.

Authorities in Britain refused last night to say if explosives were found at the East Midlands Airport – though early reports suggested it had been given the all-clear – but President Obama revealed the contents when he made a public statement on the terror threat.

It remained unclear how much explosive had been used and whether any other dangerous material, such as biological material, was included. US authorities said the devices had been made "inert".

The White House counter-terrorism adviser John Brennan said the explosives "were in a form that was designed to try to carry out some type of attack", but he provided no further details. "The forensic analysis is under way," he said. "From the initial analysis that was done, the materials that were found in the device that was uncovered were intended to do harm."

He said Saudi Arabia had provided vital information that "helped underscore the imminence of the threat emanating from Yemen".

The President instructed officials to take "whatever measures were necessary" to protect Americans and said the discoveries underlined "the necessity of remaining vigilant against terrorism", though he stopped short of openly blaming al-Qa'ida. His advisers, however, were increasingly certain that al-Qa'ida was the source and Ross Rice, an FBI spokesman, said both packages had been sent from the same address in Yemen. Mr Obama added that President Saleh of Yemen had pledged the full cooperation of the Yemeni government in the investigation.

Direct flights from Yemen to Britain were suspended by Gordon Brown in January and Mrs May is now looking at indirect flights. The former home secretary John Reid said the alerts served as a warning against reducing security measures at British airports. He said: "Today's incident is a cautionary tale for those who want to reduce essential security measures."