DOHA (Reuters) - Bahrain said on Thursday it had dismantled an Iranian-linked cell plotting attacks on its territory, arresting five suspects after finding bomb-making materials, guns and knives in their houses.

The Gulf Arab kingdom has been beset by a growing rift between its Shi'ite Muslim majority and its Sunni rulers.

Police said the five men had received military training in Iran and Iraq, according to a statement by Bahrain's interior ministry. There was no immediate comment from Tehran or Baghdad.

Bahrain, home to the U.S. Navy's Fifth Fleet, frequently accuses Iran, a Shi'ite theocracy, of being behind bomb attacks targeting security services and fomenting Shi'ite protests.

Iran denies interfering in Bahrain, although it acknowledges support for opposition groups seeking greater rights for Bahrain's Shi'ites.

The Shi'ite community led Arab Spring protests in 2011 that were put down by the government with help from neighboring Saudi Arabia.

Since June, Bahrain has taken a series of steps that activists describe as a renewed opposition crackdown, including arresting prominent activist Nabeel Rajab and stripping top Shi'ite cleric Isa Qassim of his citizenship.

U.N. Secretary-General Ban Ki-moon said on Tuesday that Bahrain's recent decision to dissolve the main opposition group, al-Wefaq, risked escalating tensions.

(Reporting by Tom Finn; editing by John Stonestreet)