Thailand's army said on Monday it had detained several people for questioning over a wave of deadly bombings in some of the country's best known-beach resorts that killed four people and wounded dozens, including tourists.

Last week's blasts came days after Thais voted to accept a military-backed constitution that paves the way for an election at the end of 2017.

No group has claimed responsibility, although police and the government have ruled out ties to foreign groups, linking the bombings to an unspecified domestic issue.