MANAMA, Bahrain - A Bahrain court sentenced eight people to prison terms of up to 15 years Sunday after they were accused of plotting with suspected Iranian agents to topple the Gulf kingdom’s ruling system, a defense lawyer said.

The convictions - which include three activists put on trial in absentia - reflect mounting claims by Gulf Arab states that Iran has links to the Shi’ite-led uprising against Bahrain’s Sunni dynasty. Iranian leaders have denounced crackdowns against protesters in Bahrain but deny any active aid to the demonstrations that began 15 months ago.

The group was accused of plotting with a foreign country - a clear reference to Iran - to bring down Bahrain’s Western-allied monarchy. The people also were suspected of planning possible attacks on high-profile targets such as the Interior Ministry headquarters and the causeway connecting Bahrain with Saudi Arabia, which is Iran’s main regional rival. They denied the charges.

The defense lawyer, Mohsin al-Alawi, said the court sentenced six people to 15 years in person. Three of those were sentenced in absentia, including the son of jailed activist Hassan Mushaima.

Mushaima is fighting to overturn a life sentence imposed last year because of links to the protests in the strategic island nation, which is home to the US Navy’s Fifth Fleet.

Alawi says two others received lesser sentences and were freed because they had already spent six months in detention.