0231 GMT August 22, 2019
The detention of Chief Justice Abdulla Saeed and another Supreme Court judge dramatically raised the stakes after Yameen refused to comply with the court's order to release political dissidents, AFP reported.
It was the latest twist in a political battle that has plunged the tiny Indian Ocean nation into crisis.
Yameen, facing threats from a galvanized political opposition to impeach him for alleged corruption, had earlier ordered a shutdown of parliament. In a televised address to the nation, the president accused the judges of being part of a plot to overthrow him.
"I had to declare a national emergency because there was no other way to investigate these judges," he said.
"We had to find out how thick the plot or coup was."
Yameen has presided over an escalating crackdown on dissent that has battered the image of the nation, and left almost all the political opposition jailed since he came to power in 2013.
On Monday he ordered the arrest of his estranged half-brother and former president Maumoon Abdul Gayoom, who had sided with the main opposition.
The 80-year-old – president for 30 years until the country's first democratic elections in 2008 – was taken from his home in the capital Male around midnight on Monday, hours after the government announced a 15-day state of emergency.
"I have not done anything to be arrested," Gayoom said in a video message to supporters posted on Twitter.
"I urge you to remain steadfast in your resolve too. We will not give up on the reform work we are doing."
The exiled leader of the Maldives opposition, Mohamed Nasheed, accused Yameen of acting illegally.
"President Yameen has illegally declared martial law and overrun the state. We must remove him from power," said Nasheed, the first democratically elected leader of the Maldives, in a statement issued Tuesday.
"We would like the Indian government to send an envoy, backed by its military, to free the judges and the political detainees."
Nasheed was jailed in 2015 after he was convicted on a terrorism charge widely seen as politically motivated. He has been in exile since 2016 when he travelled to the UK for medical treatment and was granted asylum there.
He has repeatedly accused Yameen of corruption and pledged to return from exile and run for president in elections due to be held later this year, after the Supreme Court last week quashed his terrorism conviction.
On Tuesday he said he was calling on India to send troops to the strategically located archipelago, which has grown increasingly close to regional rival China under Yameen's leadership.
Tuesday's arrests follow the court's shock decision last Thursday to order the release of political dissidents and quash the convictions of Nasheed and other exiled opposition figures.
The judges also ordered the government to restore the seats of 12 legislators sacked for defecting from Yameen's party, a move that effectively gave the opposition a majority in parliament and the power to impeach the president.