At least four people have been killed and more than 20 people injured in a series of blasts targeting tourist resorts in Thailand.
A wave of bombings were carried out in four main locations, with witnesses reporting at the site of one attack the devices had been hidden in plant pots.
They are believed to have been detonated remotely using mobile phones.
Investigators found ball-bearings at the scene which they think were put in the bombs to cause maximum injury.
Thai police said they had intelligence pointing to imminent attacks, but the timing had not been known.
But why now, who is responsible and what does it mean?
Why?
Homemade bomb have been used by attackers in Thailand in the past at times of political unrest.
But since the military took power in a coup in 2014, such attacks have been rare.
Last week, Thais voted in a referendum which approved a new constitution which will strengthen the military's influence.
"This is not the standard of democracy we would expect in this day and age," Abhisit Vejjajiva, leader of the second largest party, the Democrats, told the BBC, "but I respect the wishes of the people who voted."
While it is not clear yet what will be in these laws, established political parties fear it may require them to dissolve and reform - possibly leading to fragmentation into smaller parties.
Criticism
Amnesty International has expressed concern at the referendum.
It claims authorities have arbitrarily arrested scores of people, cancelled or disrupted peaceful assemblies and taken a television station off air in recent weeks, "marking just the most recent undue restrictions on the rights to freedom of expression, peaceful assembly and association".
“If people cannot speak their minds freely or take part in political activities without fear, how can they meaningfully engage in this referendum?” said Josef Benedict, Amnesty International’s deputy director for South East Asia and the Pacific.
“What we are seeing are not temporary measures that create peace and order as the authorities have argued, but a constant criminalisation of peaceful dissent designed to silence views that the authorities do not like.”
In a recent case, Amnesty said 11 people were taken into military custody after being accused of distributing letters criticising the draft constitution.
“They have since been handed over to the police and informed that they will be tried in a military court for sedition, criminal association and violating Thailand’s referendum act,” it said.
The human rights group claims Thai authorities have put in place "a series of undue restrictions that are contrary to the country’s obligations under international human rights law".
Initially cast as temporary measures, they have become entrenched practices that are "excessive, unnecessary and unjustifiable", it says.
"At a time when the Thai authorities should be facilitating a space for a free and informed public debate, they have continued with a root and branch onslaught against the peaceful exercise of the rights to freedom of expression, association and peaceful assembly," Mr Benedict continued.
Meanwhile, reports say at least three university events organised to discuss the referendum were cancelled under apparent pressure from the authorities.
Amnesty says a university professor was also told by the Election Commission to stop expressing his views on the draft constitution.
"These cancellations follow a pattern of government obstruction of public events deemed critical of the draft constitution and the referendum process."
According to Amnesty, on April 19th, Thai Prime Minister Prime Minister Prayut Chan-O-Cha said of critics of the draft constitution: "They have no rights to say that they disagree…I don’t allow anyone to debate or hold a press conference about the draft constitution. Yet they still disobey my orders. They will be arrested and jailed for 10 years."
But the problem runs deeper than the country’s new constitution.
Southern unrest
Decades of unrest in Thailand's Muslim-dominated south spiralled into an Islamist insurgency in the early 2000s.
Insurgent groups adopting separatist or jihadist rhetoric have targeted security forces, government workers and local Buddhist communities in the past.
To now, the violence has largely been contained within the provinces of Pattani, Yala, Narathiwat and Songkhla.
These are areas the Irish Department of Foreign Affairs specifically recommends to avoid "all travel to or through".
No one has claimed responsibility for the series of bombings, but the blasts coincided with the birthday of Thai Queen Sirikit.
Some experts believe this may point to domestic, as opposed to international, terrorism.
Others believe it is designed to take a chunk out of their massive tourism budget.
Tourism
In the wake of the attacks, Prime Minister Prayut Chan-o-cha instructed local authorities to "step up security at key locations" throughout Thailand as a "preventive measure and to ensure safety and security for tourists and local residents".
Following the May 2014 coup d'etat, tourism decreased by up to 7% - but this was said to be seeing recovery.
According to the World Bank, the country has seen a sharp increase in the number of tourists since 1995.
In 2014, the country saw 24,810,000 international tourists visit – up from just 6,952,000 in 1995.
The figure even includes a slight fall-off, as Thailand took in 26,500,000 tourists in 2013.
The World Travel and Tourism Council (WTTC) says the direct contribution of tourism to Thai GDP in 2014 was THB1,037.3bn (€26.7bn).
That is roughly 8.6% of income for the country’s economy.
The WTTC says this was forecast to rise by 3.4% in 2015.
“This primarily reflects the economic activity generated by industries such as hotels, travel agents, airlines and other passenger transportation services (excluding commuter services),” the WTTC says.
“But it also includes, for example, the activities of the restaurant and leisure industries directly supported The direct contribution of travel and tourism to GDP is expected to grow by 6.7% pa to THB2,045.0bn (11.7% of GDP) by 2025”.
