Many Britons are facing an anxious wait for news of friends and relatives following a series of bombings in the Indian city of Mumbai (Bombay).
More than 100 people were killed in the explosions, officials said
Telecommunications have been affected by seven blasts on the train network which killed at least 160 people.
The Foreign Office said there were no reports of UK casualties, but it was considering whether to set up a helpline for worried people in the UK.
The Hindu Forum of Britain said it was also pondering the best way to help.
It was discussing options with the Indian High Commission in London, it said.
The forum set up a helpline following the Asian tsunami, when it received thousands of calls.
Readers of the BBC News website have reported difficulties in contacting relatives in the city as telephone lines became jammed.
Sanjay from Bristol said his family had sent a text message to him saying landlines were malfunctioning.
Nimesh, from Leicester, is waiting for news of his cousin.
He said: "All communications are down in India. We have been trying to communicate ever since the news broke out."
Harpreet, from Birmingham, had better luck, getting through to a friend.
"Her husband is traumatised from the blasts. He was on the same train when the first-class compartment exploded. He saw an orange flame and then smoke.
"People were jumping out of the running train. When he got off, he saw bodies on the tracks.
"She told me that her husband is too shocked to even believe that he saw it with his own eyes," Harpreet said.
Prime Minister Tony Blair condemned what he called "brutal and shameful attacks", saying there could "never be any justification for terrorism".
"Our thoughts are with the victims and their families.
"We stand united with India as the world's largest democracy, through our shared values and our shared determination to defeat terrorism in all its forms."
A Foreign Office spokeswoman said its staff were meeting to decide whether to send a rapid reaction team to the city.
She said staff in India were monitoring the situation.
She said a helpline would be set up if there were a lot of calls to the Foreign Office's main switchboard.
Hindu Forum spokesman Ramesh Kallidai called for western governments to rally behind India.
"The international communities need to take these blasts as seriously as the London blasts last year," he said.