Speaking with Sky television on Thursday, British Foreign Secretary Philip Hammond said that the Sinai Peninsula affiliate of the self-proclaimed "Islamic State" group had claimed responsibility for downing the jet straight after the crash.

"We've looked at the whole information picture, including that claim, but of course lots of other bits of information as well, and concluded there is a significant possibility," Hammond said in response to a question about whether he thought "IS" militants were behind the disaster.

Earlier, following a Wednesday meeting of the UK government's crisis response committee, Hammond had said there was a possibility the crash was caused by a bomb on board the aircraft. IS has repeatedly insisted it brought down the plane.

Russia says bomb theory is speculation

The Kremlin has responded to the British remarks by saying only the official investigation could determine what had happened.

Dmitry Peskov, a spokesman for Russian President Vladimir Putin, told reporters on Thursday that while Moscow "cannot rule out a single theory" about the crash, he insisted that singling one out at this stage was merely speculation.

The Airbus A321 crashed in the Sinai Peninsula on Sunday shortly after it took off from the holiday resort of Sharm el-Sheikh on the way to the city of St. Petersburg in Russia. All 224 people on board were killed. Most of the passengers were Russians heading home from vacations at the Red Sea.

Flights suspended, tourists stranded

The UK and Ireland have suspended all flights to and from the resort indefinitely pending a review of security.

London has called an emergency cabinet meeting and is planning to evacuate its tourists from the resort. News agency AFP estimates about 20,000 Britons were currently there.

"We're working with the airlines and the Egyptian authorities now to put in place emergency short-term measures that will allow us to safely bring back the British tourists who are there in Sharm," Hammond said on Sky News television. Those measures would "allow us to screen everything going on to those planes, double-check those planes."

Almost a million Britons visit Red Sea resorts each year.

Tourism vital for Egypt

Egyptian officials have stressed the need to wait for the results of an international investigation. Tourism is a key earner for Egypt. The country's economy is struggling to recover from years of political conflict.

The British acted "too soon," Hany Ramsay, deputy head of Sharm el-Sheikh's airport told The Associated Press, adding that other countries might follow and suggesting that there may be political and commercial motives at play.

"They want to hurt tourism and cause confusion," he added.

Egyptian President Abdel-Fattah el-Sissi is in Britain for an official visit and was expected to hold top-level talks on Thursday.

Kogalymavia, the Russian airline which operated the crashed plane under the name Metrojet, has suspended all flights of its Airbus A321 aircraft.

First funeral held

The first memorial service has been held for a victim of the crash. Nina Lushchenko was given a farewell in a medieval church in the northern Russian city of Veliky Novgorod. The 60-year-old was remembered as a good mother and grandmother.

Russian rescue workers were continuing to search for victims' remains, combing an area of about 40 square kilometers (15 square miles.) Russia's Emergency Situations Minister Vladimir Puchkov said the operation should be complete by Thursday evening.

se/kms (AP, AFP, Reuters)