The Islamic National Accord Association (INAA) "will face legal measures after it organised an unlawful demonstration yesterday," Information Minister and State Minister for Foreign Affairs Muhammad Abd al-Ghaffar was quoted by the daily Al-Ayyam as saying on Saturday.
Newspapers carried a similar warning issued by the interior minister late on Friday after thousands of people took to the streets of Sitra, the archipelago's third largest island located south of Manama, in response to the INAA's call to press for constitutional reforms.
INAA leader Shaikh Ali Salman led the march, in which representatives of three other political groupings allied with his association - the leftist National Democratic Action Association, the Nationalist Democratic Rally, which is a pan-Arab nationalist group, and the Islamic Action Association, a Shia grouping - also took part.
Abd al-Ghaffar (L) did not spell
out the measures
The four groups have repeatedly objected to the legislative powers accorded to the Majlis al-Shura, or consultative council.
They are demanding that legislative powers, as well as the authority to act as watchdog over the executive, be confined to the elected house of parliament, which, like the nominated council, has 40 members.
Bahrain's elected chamber, scrapped in 1975, was revived in 2002 as part of reforms spearheaded by King Hamad bin Isa Al Khalifa which turned the Gulf state into a constitutional monarchy.
All four opposition groups boycotted the 2002 parliamentary polls in protest against the amendment to the 1973 constitution which split legislative power equally between the elected chamber and the consultative council.
The four allies also argue that the constitution, promulgated by royal decree after it was amended in 2002, should also be ratified by the elected parliament.
"The nature of the measures will be determined by legal experts"
"Our demands are legitimate, (we want) constitutional amendments," chanted the demonstrators, who numbered more than 10,000, according to independent estimates.
Abd al-Ghaffar did not spell out the "measures" which would be taken against the INAA, the main political formation of Bahrain's majority Shia Muslims, amid speculation that the government could either order its temporary suspension or withdraw its licence to operate.
"The nature of the measures will be determined by legal experts," he told Al-Ayyam.
Newspapers cited a statement by Interior Minister Rashid bin Abd Allah al-Khalifa also warning that the INAA would be subjected to "the appropriate legal measure" after defying his ministry's ban, which he said was prompted by "the tension and security threats" facing the region.