At least four people have died and dozens were injured following a series of coordinated bomb attacks across tourist towns in Thailand.

Four bombs exploded in the resort town of Hua Hin, and several blasts were reported in Phuket. Others explosions also occurred in Surat Thani, Phang Nga and Trang. The bombs were detonated using mobile phone timers in each attack.

Witnesses at one site in Hua Hin said a bomb had been hidden in plant pots on a street filled with restaurants and bars.

Sky News also reports that investigators found ball-bearings at the scene which they believe were put in the bombs to cause maximum injury.

One British national is reported to have been injured and more foreign nationals were among the 35 injured.

The British embassy in Thailand has updated its travel advice urging tourists to exercise “extreme caution” and to avoid public places.

The Foreign and Commonwealth Office said: “There have been multiple explosions in tourist areas across Thailand on August 11 and 12.

“We are in close contact with local authorities and urgently seeking more information. You should exercise extreme caution, avoid public places, and follow the advice of local authorities.”

Police have ruled out international terrorism and said links to the southern insurgency were unclear, the BBC reports.

A statement from Abta said: “Following the explosions in various locations across Thailand on August 11 and 12, Abta is advising travellers in the country to follow Foreign & Commonwealth Office (FCO) advice, which includes exercising extreme caution and following the advice of local authorities.
“August is the tourist low season in Thailand, with the majority of visits taking place in the winter months when the weather is at its best. Abta is aware of only very small numbers of customers on holiday with its Members. However, Thailand is a popular destination for backpackers and independent travellers; and in 2015 there were 320,000 holiday visits to Thailand by British people.
“The overall level of Foreign Office advice has not changed and travel bookings will be subject to the normal terms and conditions.”