Celebrations to mark the king's coronation were held this week
Several people allegedly planning to detonate homemade bombs during Bahrain's national celebrations have been arrested, security officials say.
According to media reports from the Gulf state, the attacks were planned to take place on the anniversary of the king's coronation.
It is not clear how many people were arrested in Tuesday's operation.
The bombs would have contained "large amounts of small iron balls", said a statement quoted by AFP news agency.
Bahrain, linked to Saudi Arabia by a causeway, is ruled by King Hamad bin Isa al-Khalifah.
There are long-running tensions between Bahrain's ruling Sunnis and the Shia Muslim majority. On occasion, these have spilled over into civil unrest.
It is a close ally of the US and is home to the American navy's Fifth Fleet.
No major terrorist attacks have ever been carried out on its soil.