Male, Oct 24 (IANS): Maldivian Vice President Ahmed Adheeb Abdul Ghafoor was arrested on Saturday after he was charged with "high treason" over his involvement in a blast on a speedboat carrying President Abdulla Yameen Abdul Gayoom last month.

Adeeb was in detention and is being charged with high treason, Home Minister Umar Naseer said on Twitter.

He was arrested as soon as a flight carrying him from Singapore landed at the Ibrahim Nasir International Airport (INIA), Haveeru online reported.

Security has been tightened in the capital Male amid fears of "turmoil" triggered by the arrest, police said.

Adeeb has denied all charges.

President Abdulla Yameen Abdul Gayoom and First Lady Fathimath Ibrahim were travelling to Male from the airport on September 28 when the explosion took place. They had returned home that morning after concluding their visit to Saudi Arabia to perform the annual Haj pilgrimage.

The president was unhurt, but the first lady suffered a spinal fracture while presidential secretary Fathimath Mohamed Solih and bodyguard Abdu Nasir received minor injuries including burns. The first lady still remains in hospital.

Three others were also arrested earlier suspected of being involved in the attack.

Soon after the blast, speculation began to grow that Adeeb was involved, sources said. Under the Maldivian constitution, the vice-president succeeds the president if he dies, is incapacitated or resigns.

Adeeb, the fifth vice president of Maldives, assumed office on July 22. He took charge after his predecessor Mohamed Jameel Ahmed was impeached also due to treason charges.