If the perpetrators were targeting the two statues deliberately, they were likely Islamic hardliners. Besides removing supposed temptations to idolatry, Islamic jihadists want to destroy the artifacts of non-Muslim civilizations, because doing so testifies to the truth of Islam, as the Qur’an suggests that the destroyed remnants of ancient non-Muslim civilizations are a sign of Allah’s punishment of those who rejected his truth:
Many were the Ways of Life that have passed away before you: travel through the earth, and see what was the end of those who rejected Truth. (Qur’an 3:137)
This is one of the foundations of the Islamic idea that pre-Islamic civilizations, and non-Islamic civilizations, are all jahiliyya — the society of unbelievers, which is worthless. Obviously this cuts against the idea of tourism of ancient sites and non-Muslim religious installations. V. S. Naipaul encountered this attitude in his travels through Muslim countries. For many Muslims, he observed in Among the Believers, “The time before Islam is a time of blackness: that is part of Muslim theology. History has to serve theology.” Naipaul recounted that some Pakistani Muslims, far from valuing the nation’s renowned archaeological site at Mohenjo Daro, saw its ruins as a teaching opportunity for Islam, recommending that Qur’an 3:137 be posted there as a teaching tool.
“Small bombs hit Thai beach, damaging Golden Mermaid,” Associated Press, December 27, 2018 (thanks to M.):
Police in Thailand are investigating two small bombs, one of which damaged an iconic statue on a popular beach in the country’s south.
Police in Songkhla province say they’re looking into whether the bombs were related to a Muslim separatist insurgency that has wracked nearby provinces since 2004, taking almost 7000 lives.
The Golden Mermaid statue, which is an unofficial symbol of the province, was damaged by one bomb. The other took place about 300 metres away, near the beach’s Cat and Mouse sculpture.
The insurgency has mostly affected the three southernmost provinces of Pattani, Yala, and Narathiwat, which have Muslim majorities in predominantly Buddhist Thailand….