We know who is behind this

Thai police investigating a wave of bombings that rocked tourist destinations and killed four people yesterday said they know who was behind the attacks.

Police said two men have been held for questioning over the blasts in Hua Hin -- a resort town struck by four of the bombs -- with a third arrested over a suspected arson attack in Nakhon Si Thammarat province.

"Our investigation is progressing. We know who was behind it," deputy national police spokesman Piyapan Pingmuang told AFPyesterday, declining to provide further details on those detained or offer a possible motive.

Some analysts suggest the bombs were the work of Muslim rebels waging a long-running insurgency in Thailand's southern tip.

Police have rejected that theory and also ruled out international terrorist groups, insisting the bombings were acts of "local sabotage".

At least 11 bombs and a series of suspected arson attacks ripped across seven southern provinces on Thursday and Friday, killing four locals and wounding more than 30 people including European tourists.

Thai police over the weekend found and defused five explosive devices that had failed to detonate.

No one has claimed responsibility for the blasts, which are seen as an affront to a military government that prides itself on having brought some stability to Thailand since its 2014 coup.

The attacks came just days after Thais voted to accept a military-backed constitution that the ruling junta, which seized power in 2014, has said will lead to an election by the end next year.

Analysts say suspicion would inevitably fall on enemies of the ruling junta aggrieved by the referendum results.

Fears that followers of former prime ministers Thaksin Shinawatra and his sister Yingluck Shinawatra could be blamed prompted a senior figure in their Puea Thai Party to issue a sharp denial on Saturday.