European soccer's governing body said the Champions League Group D match between Galatasaray of Turkey and Italy's Juventus, scheduled for next Tuesday in Istanbul, had been put back a week to December 2.
The UEFA Cup second round, second leg match between Israel's Maccabi Haifa and Valencia of Spain, due to be played in Izmir next Thursday, has also been postponed with a new date and venue yet to be arranged.
"UEFA has decided to postpone the most imminent matches coming up in competitions in Turkey next week, given the seriousness of the incidents that took place in Istanbul this morning and the current confusion on the ground," director of competition operations, Jacob Erel, said in a statement on the European governing body's website.
The UEFA Cup tie, with Maccabi as the home team, was originally moved to Turkey because of security concerns in Israel.
Suspected Islamist suicide car bombers killed at least 26 people and wounded hundreds in a strike against British targets on Thursday.
Bombings of the British consulate and HSBC Bank headquarters in Istanbul appeared to have been timed to coincide with talks in London between U.S. President George W. Bush and British Prime Minister Tony Blair, his chief ally in the war in Iraq.
BEST SOLUTION
Maccabi Haifa and Valencia both gave their full support to UEFA's decision to postpone their second round tie.
The Israeli culb issued a statement saying: "Maccabi Haifa feels the pain resulting from the tragic events in Istanbul this morning and UEFA's decision (to postpone the match) was the obvious one to take under the circumstances.
Valencia president Jaime Orti told his club's website: "It is the best solution for both teams. It is the most logical solution given that security has to be the number one priority.
"Now we will be working on choosing the most suitable alternative date and venue for both Valencia and Maccabi."
However, there was some confusion over new arrangements for the match. Haifa said it would be played on December 4 and could still take place in Izmir, while Valencia said it was likely to be on December 11 with Cyprus mooted as a possible venue.
Haifa clearly see the postponement as another chance to persuade UEFA that they should be allowed to play in Israel.
"Because the announcement does not specify a venue for the match, we hope this opens the door to changing UEFA's decision not to hold matches in Israel," Haifa's statement said.
The club's spokesman Ofer Harel added: "Following the decision to postpone the match to December 4, we will ask UEFA to host it in Israel, although we will also look at Cyprus, Romania and England too," Harel said.
Ukraine could be another option, Haifa said.
SECURITY SITUATION
UEFA said they would keep an eye on developments in Turkey in case they needed to make alterations to other fixtures like Chelsea's Champions League visit to Besiktas scheduled for December 9 in Istanbul.
"Over the next few days, we will be closely monitoring the overall security situation in Turkey...and will remain in constant contact with the clubs and national associations concerned regarding any forthcoming matches scheduled in Turkey," Erel said.
Chelsea said on Thursday that they had decided not to take up their ticket allocation for the Group G match.
"We had been working closely through UEFA with the Turkish authorities to ensure that it was safe for our fans to travel," Chelsea's interim chief executive Paul Smith said.
"However, today's bombings of British targets, the advice just issued by the Foreign & Commonwealth Office, and the generally unsettled situation there, has prompted us to make this final decision," Smith told Chelsea's website.
