Six of those arrested on Wednesday were freed last month after being briefly detained for similar reasons.

The suspects "prepared a plan to carry out attacks using explosives against government, economic and tourist facilities", said an interior ministry statement.

The men wanted to "spread panic among the population, create disorder and expose the national economy and foreign investments to danger," the statement added. 

The six were released without charge on 23 June after being arrested the previous day for planning to carry out "grave acts" in the tiny Gulf country on behalf of al-Qaida. 

A Bahraini official had said last week the suspects were still under judicial investigation. 

Motivations questioned

Abd Allah Hashim, a lawyer representing four of the detainees, said the charges were politically motivated. 

"The charges have been revived due to the US move to recall nationals from Bahrain. It seems there's some pressure from the US on the Bahrain government to take extra care in dealing with this case"

Abd Allah Hashim,
lawyer

"All the information given is old and was extracted last year when some of them were first arrested on similar charges," he said.
 
"The charges have been revived due to the US move to recall nationals from Bahrain. It seems there's some pressure from the US on the Bahrain government to take extra care in dealing with this case."

Previous alerts
 
On 2 July, Washington issued a "terror" alert in Bahrain, which
hosts the US Navy's Fifth Fleet and is home to some 5000 Americans, most of them military personnel. 

The Pentagon ordered the departure of dependents of military
personnel and non-emergency defence officials from Bahrain, because of credible reports that extremists were planning attacks on US interests. 

The US State Department also authorised the departure of
dependents and non-emergency employees at its embassy here. 

A US military spokesman said that the move involves 930 people who are "temporarily relocating" to the United States in a process that would take about a fortnight. 

Washington bills Bahrain as a "major non-NATO ally".