UK, U.S. warn of Turkey travel
Straw: Blasts had hallmark of al Qaeda
British Foreign Minister Jack Straw calls bombings "terrorist attacks"
(CNN) -- The U.S. and Britain have warned their citizens to proceed cautiously in Istanbul after terrorists attacked the British Consulate and a British-owned bank, killing at least 26 and wounding hundreds.
"More attacks are possible, as well as the possibility of fires, gas line explosions and collapsing buildings near the bomb sites," said the U.S. Embassy in Ankara.
The embassy urged Americans to avoid Western-oriented businesses and religious institutions "until further information is available."
"Due to these dangers, the Consulate General in Istanbul strongly advises that all American citizens stay away from these areas. The U.S. Consulate in Istanbul has suspended normal visa services, but is fully staffed for emergency assistance.
"Although there is no evidence of immediate threat to the U.S. Consulate General building in (the Istanbul neighborhood of ) Istinye, barring a personal emergency, Americans are advised to defer visits to the consulate. Embassy Ankara and Consulate Adana remain open for regular business."
The message warns of a worldwide caution for Americans and the attraction of soft targets for terrorists. On Saturday, two Istanbul synagogues were bombed, and 25 people were killed.
"All American citizens are urged to continue exercising extreme caution and maintaining a low profile throughout Turkey. We reiterate Department of State advice to American citizens to take prudent steps to ensure their personal safety," the embassy said.
"Remain vigilantly aware of surroundings, listen to news reports, avoid crowds and demonstrations, keep a low profile, and vary times and routes for all travel," the embassy said.
In a travel advisory, Britain's Foreign Office said "until further notice, the British Consulate in Istanbul will not be able to provide the full range of services. There is a high threat from terrorism in Turkey.
It advised "against all but the most essential travel to Istanbul, until the situation becomes clearer."
British Airways said though that a flight to Istanbul on Thursday would continue as scheduled despite the warning.
Britain urged visitors to be "vigilant in all parts of the country, and especially in the vicinity of potential terrorist targets."
Other attacks cited include small explosions this spring outside two HSBC branches in Istanbul and a blast at an Ankara cafe killing one person in May. There were explosions at two branches of McDonald's in Istanbul earlier this year.
In April, the Foreign Office said there was an explosion at the visa section of the British Consulate-General in Istanbul, causing minor material damage, but no casualties.
Three small devices also exploded in Izmir, one of which was near the British Consulate. There were no casualties and no significant damage.
The Foreign Office issued a telephone number for anyone wanting news of friends or relatives who might have been caught up in Thursday's blasts. The number when dialing from outside Britain is +44 20 7008 0000.