A Foreign Office rapid deployment team is being sent to Turkey to help Britons injured after three bombs hit a holiday resort there.
Ten British tourists and 11 Turks were hurt when one of the bombs blew apart a minibus in the Marmaris resort, where security has since been stepped up.
The injured Britons are in hospital, with four in a serious condition. None has life-threatening injuries.
The Kurdistan Freedom Falcons has said it carried out the attacks.
The group, known as TAK, said the blasts were "in revenge for the imprisonment of Abdullah Ocalan", the figurehead of the fight for Kurdish independence in south-eastern Turkey. The claims have not yet been verified.
No injuries resulted from two other blasts at the resort at the same time.
Two British Red Cross support staff will be among the group of experts sent to Turkey by the British Foreign Office to help with the aftermath of Sunday night's explosions.
British Red Cross workers Christopher Clark, from Grantham, Lincolnshire, and Maria Downs, from Sheffield, will provide emotional and practical help.
British Red Cross spokesman Leigh Daynes said: "Our delegates will be on hand to offer them any practical or emotional help they might request to see them through these first few difficult days.
"Together with the Foreign Office, the Red Cross works to ensure people are cared for emotionally as well as practically."
One of the British tourists being treated in hospital, Suzanna Beckford, from Birmingham, said: "I'm still in shock. I just want to know who caused it, why they did it to us - we haven't done anything."
At least three people have been killed in another blast in the southern resort city of Antalya, according to reports.
The British ambassador in Turkey, Sir Peter Westmacott, who has travelled to Marmaris, told BBC News that as far as he knew "there were no British casualties" in the latest attack.
Another bomb in Istanbul, a roadside device, exploded late on Sunday night and injured six Turkish nationals.
Turkish police in Marmaris said only one device apparently detonated properly, on the minibus which was travelling down a busy main street.
BBC correspondent Sarah Rainsford said that the whole area has now been cordoned off by police.
Turkey blasts: Advice
Britons worried about relatives in the area can call the Foreign Office helpline on 020 7008 0000
UK tour operator Thomas Cook said five of its customers are among the injured
Tour operator First Choice says it does not believe any of its customers were caught in the blasts
The other two devices reportedly went off in rubbish bins, but no-one is said to have been injured from these explosions.
A Foreign Office spokeswoman said she believed one explosion occurred by the harbour. It is not yet clear where the third blast happened.
She added consular staff were on the ground in the area.
She said it was likely that the 10 injured were holidaymakers but that British nationals could be living in the area.
Despite the attack, the Foreign Office's travel advice for the thousands of people who visit Turkey each week has remained largely unchanged.
It warns of a high terror threat, but does not dissuade people from travelling to the country.
Tayfun Sentop, a spokesman for the Ahu Hetman hospital, where six of the injured have been taken, said their injuries were "nothing serious".
"They have general body traumas and nothing very serious - they are having treatment as inpatients," he told the BBC.
And Julie Midgley - another Abu Hetman representative - said the six at the hospital, who range from a seven-year-old boy to a 65-year-old woman, had spent a "comfortable" night and "their spirits seem to be good".
The other four Britons were admitted to the Caria hospital.
Suzanne Poyraz, foreign operations manager at the hospital, said they had suffered burns and shrapnel injuries to their legs and lower extremities.
"They are not too badly injured. None of them have got life-threatening injuries, but of course they are terribly shocked and two have got particularly nasty injuries to their legs."
There is no indication, as yet, of who carried out the attacks
She said a couple, a man aged 38 and a woman aged 44 had suffered minor injuries.
A 13-year-old girl and a 73-year-old woman had both undergone surgery.
She said the explosion appeared to come from the bottom or from outside the bus they had all been travelling in.
A couple told BBC News they were "frustrated" by the lack of information they had received.
"No one has really told us what is going on. We have not heard anything, we have only ever spoken to our [holiday] rep about it and the hotel.
"We have not seen or spoken to anyone else, we have not seen any news so we do not know what is going on.
"They should have given us more information and advice instead of saying it's no big deal when it obviously is.
"You get really nervous when you are walking around, I feel a bit apprehensive.
"We went one of them [a minibus] only once since we got here - we won't be going on them again, definitely not."
ATTACKS IN TURKEY
25 June: 4 killed, 25 injured in southern resort of Antalya
16 April: 31 injured in Bakirkoy district of Istanbul
31 March: 1 killed, 13 injured in Istanbul's Kocamustafapasa district
9 February: 1 killed, 16 injured at internet cafe in Istanbul's Bayrampasa district
18 November: One killed and 11 injured in the Beylikduzu district of Istanbul
Another witness, Danielle Pearson, told Sky News she saw "the remains of what was left".
"There were ambulances and police cars going everywhere.
"It was the usual holidaymakers walking about, everybody out enjoying themselves."
The Federation of Tour Operators (FTO) said its members currently have about 14,000 customers in the resort area.
In a statement, it said: "Our current understanding is that five customers of FTO members - all with Thomas Cook Holidays - have been hospitalised, and Thomas Cook staff are in close contact and offering help and support.
"The FTO will continue to liaise with the UK Foreign and Commonwealth Office. No hotels have been affected by the incident."
A spokesman said holidays were "continuing as normal" and there had not been a rush to cancel holidays or return home.
"Members are not reporting customers wishing to return early in any great numbers - just a handful," he said.
It is currently peak season in Marmaris, which is a popular holiday destination among Britons.
The town is relatively westernised with a large number of bars, restaurants and nightclubs.
There is no indication, as yet, of who carried out the attacks.
Kurdish separatists, Islamic militants and leftist extremists have all carried out attacks in Turkey in the past.
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