Maldives officials said Tuesday that last month's explosion aboard a boat carrying President Abdullah Yameen was an assassination attempt.
Officials initially blamed the September 28 blast on a mechanical problem, but evidence turned up by forensics experts showed someone intended to kill Yameen, officials said.
Two security officers have been arrested, but it was not yet clear whether they had any part in the plot.
The blast shook the boat carrying the president and his entourage as it sped toward the capital, Male. Yameen was not hurt, but his wife and two others were wounded.
The Maldives, a world-famous tourist site, has been shaken by the recent arrest and trial of former President Mohamed Nasheed. A court sentenced him to 13 years in prison for ordering the arrest of an allegedly corrupt judge when he was president three years ago.
The United Nations ruled last week that the trial was illegal and ordered Nasheed's release.
Human rights lawyers say they fear the Maldives is turning away from moderation toward extremism, noting that thousands of young men from the islands have joined Islamic State.