Kuwait on Tuesday charged 24 people suspected of links to Iran and Shiite militia group Hezbollah with plotting attacks against the Gulf state, a statement by the public prosecutor said.
The men were charged with "spying for the Islamic republic of Iran and Hezbollah to carry out aggressive acts against the State of Kuwait" by smuggling in and assembling explosives, as well as possessing firearms and ammunition, the statement said, according to the AFP news agency.
They were also charged with "carrying out acts that would undermine the unity and territorial integrity" of Kuwait, and of possessing eavesdropping devices, the statement said.
Two other men were also charged in the same case, one with possessing illegal weapons and another with failing to inform authorities about the arms.
One of the suspects is Iranian and the rest are Kuwaiti nationals. Three who remain at large were charged in absentia.
Prosecutors said the suspects were linked with a "terror cell" the interior ministry said it had busted last month while seizing large amounts of weapons, ammunition and explosives.
Officials said at the time that three men had been arrested and confessed to joining an illegal group that local media reported was Hezbollah.
Media had reported that more arrests followed and the prosecutor said 22 of the suspects charged on Tuesday had received explosives and weapon training to "achieve illegal goals".
A number of suspects were accused of being members of Hezbollah which "aims to demolish the social and economic foundations of the country", the prosecutor's statement said, according to AFP.
Sunni-ruled Kuwait has traditionally had better ties with Iran than its fellow Gulf Arab states, but tensions have been rising.
Majority-Sunni Muslim Kuwait has been on alert since an Islamic State suicide bomber blew himself up at a Shiite mosque in the capital Kuwait city in late June, killing 27 people.
The charging of the suspects came two days after the head of parliament's foreign relations panel, MP Hamad al-Harashani, described Iran as the "true enemy" of Sunni-ruled Gulf Arab states and said it sought "to spread chaos" in the region.
This was not the first Iran-linked espionage ring to be spoken of in Kuwait.
In May 2013, the supreme court upheld life terms for two Iranians, a Kuwaiti and a stateless man on charges of forming a ring to spy for Tehran.
The convicts, who worked for the army, were accused of spying for Iran and passing information on Kuwaiti and American military forces in the emirate to the Islamic Republic's elite Revolutionary Guards.
Iran dismissed the accusation.
Kuwait has also arrested alleged members of the Sunni extremist Islamic State (ISIS) group, which said it was behind the June attack on the mosque.
The lower court on Tuesday set September 15 as the date when it will issue its verdict on 29 suspects in that case.
AFP contributed to this report.