Iran accused Sunni-ruled Bahrain of stoking tensions in the Gulf by making unfounded allegations against it, the official IRNA news agency reported.
"It is clear that the government of Bahrain, by repeating unfounded allegations, seeks to create a climate of tension in the region," it quoted foreign ministry spokeswoman Marzieh Afkham as saying.
"Such methods are not constructive, and do not diminish the Islamic republic's commitment to continue its policy... and regional cooperation in the fight against terrorism and extremism," she said.
On Saturday, Bahrain's interior ministry said it had detained two men accused of trying to smuggle weapons from Shiite Iran.
That announcement came hours after Bahrain, which has a Shiite majority, said it was recalling its envoy from Tehran in protest at "hostile" comments by Iranian leaders.
Last Sunday, Bahrain summoned Iran's acting charge d'affaires to protest against its supreme leader Ayatollah Ali Khamenei voicing support for "oppressed people" across the Middle East, including in Bahrain.
The previous day, Khamenei had said the nuclear deal Tehran agreed with world powers would not alter its support for the governments of Syria and Iraq, nor its backing for "oppressed people" in Yemen and Bahrain, and the Palestinians.
Manama accuses Tehran of backing opposition demands in Bahrain for a constitutional monarchy and an elected prime minister.
Iran does not hide its support for the protest movement in Bahrain, but rejects accusations of interference in its internal affairs.
Foreign Minister Mohammad Javad Zarif, in Kuwait on Sunday on a regional tour that also includes Qatar and Iraq, urged Iran's Gulf Arab neighbours to cooperate against the common threat of "terrorism, extremism and sectarianism".
Zarif also denied as "baseless" Bahrain's claims that it had detained two men for trying to smuggle weapons from Iran.
"I openly say the claims are totally wrong," he said.
"The timing of the announcement is an attempt to prevent any progress in cooperation between Iran and other Gulf states.
