Tourists are being warned to "exercise extreme caution" in Thailand after a wave of co-ordinated explosions left several people dead and dozens more wounded.
The Foreign Office updated its travel advice following multiple blasts in Hua Hin, Trang and Surat Thani and was "urgently clarifying" reports of a further explosion in Phuket.
Among the injured were 10 foreigners in the seaside resort town of Hua Hin, which was hit by two explosions on a busy street on Thursday night and by two further blasts on Friday morning.
There were also explosions in Trang on Thursday and Surat Thani on Friday which caused casualties, the FCO said, warning tourists to "exercise extreme caution, avoid public places, and follow the advice of local authorities".
An FCO spokesman said: "There have been multiple explosions in tourist areas across Thailand on 11 and 12 August. We are in close contact with local authorities and urgently seeking more information. We stand ready to provide assistance to any British nationals involved."
It is advising against "all but essential travel" to the provinces of Pattani, Yala, Narathiwat and Songkhla on the Thai-Malaysia border.
Colonel Krisana Patanacharoen, of the Royal Thai Police, said it was too soon to say who was behind the attacks but "we are sure that it is not linked to terrorism".