A series of coordinated blasts across Thailand has targeted tourist towns leaving at least four dead and many injured, with reports of more explosions.
In the popular resort town of Hua Hin, four bombs exploded over the last 24 hours. Several blasts also hit the island of Phuket on Friday.
No group has said it carried out the attacks, but suspicion is likely to fall on separatist insurgents.
The timing is sensitive, as Friday is a holiday marking the Thai queen's birthday.
The attackers appear to be focusing on areas where tourism is significant and reports of sporadic blasts are still coming in. So far the locations include:
Hua Hin is about 200km south of Bangkok while the province of Phuket is in the far south. Both places, as well as Phang Nga are known for their scenic beaches. In Surat Thani, there were two explosions in front of police stations half an hour apart.
The Ministry of Foreign Affairs is urging New Zealanders travelling in Thailand to stay vigilant after bomb blasts.
New Zealanders are advised to contact the embassy in Bangkok for help and to stay in touch with family.
Edwin Weik runs a wildlife protection charity near Hua Hin.
He went to the first of the bomb sites, recording video which he provided to police, as he told RNZ reporter Phil Pennington.
Police on Friday said they detained some suspects but ruled out international terrorism and said that any links to the southern insurgency were unclear.
The BBC's Jonathan Head in Bangkok says that if it turns out insurgents are behind these attacks it would mark a significant change of tactics after a 12-year conflict which has killed more than 6000 people, but has never targeted tourists.
Security has been tightened in the tourist areas and at airports in southern Thailand.
New Zealand's Ministry of Foreign Affairs and Trade advised citizens in Thailand to be vigilant, monitor the media for updates, follow the instructions of local authorities and keep family members abroad informed.
Tourist areas targeted
The attacks have clearly attempted to strike at Thailand's crucial tourism sector. The Hua Hin explosions on Thursday night struck a bar area popular with tourists and foreigners were among those injured.
But the choice of Hua Hin as a major target is also symbolic, the BBC's correspondent says, being known as a royal city and the king's favoured residence outside Bangkok. The blasts coincide with an important public holiday which celebrates the queen's birthday.
Brant Smith, from Canberra in Australia and on holiday in Hua Hin told the BBC people in the idyllic resort were "rattled" and there was tight security around his hotel.
Small improvised bomb attacks have frequently been used in Thailand at times of political unrest, but since the military took power in a coup in May 2014 such attacks have been extremely rare.
"The bombs are an attempt to create chaos and confusion," PM Prayuth Chan-ocha said to reporters. "We should not make people panic more."
This comes just days before the one-year anniversary of the bomb blast at the Erawan shrine in Bangkok that killed 20 people.
Last week, Thais voted in a referendum which approved a new constitution that will strengthen the military's influence in politics for many years.
Foreign embassies have advised tourists to be vigilant.