Bangladeshi President Iajuddin Ahmed has been sworn in as head of an interim government after the main political parties failed to agree a candidate.
Mr Ahmed will continue in his role as president
Installed in a televised ceremony at his office, he is charged with ensuring fairness in January's elections.
He has been trying to solve a political crisis that has led to the deaths of 18 people in two days of rioting.
His decision to take the job without opposition backing is said to be the last constitutional option available.
But there are fears that the move could trigger more protests.
A former professor of soil science, Mr Ahmed is in his seventies and had a heart bypass operation five months ago.
He will continue to perform his duties as president.
Protests 'to continue'
After the announcement that Mr Ahmed was taking on the role, which is known as chief adviser, the BBC's Roland Buerk in Dhaka said the capital's near-deserted streets filled with screaming sirens as motorcades carrying dignitaries headed to his palace.
Mr Ahmed was sworn in by Chief Justice JR Mudassir Hossain, in a ceremony attended by senior diplomats, civil servants and politicians.
But the opposition Awami League failed to attend.
It had already rejected Mr Ahmed's candidature on Saturday, on the basis that he was too close to outgoing Prime Minister Khaleda Zia's party.
Reacting to the appointment, Awami League leader Sheikh Hasina said she expected Mr Ahmed to implement electoral reform proposals submitted by the party.
"He has to prove himself as a neutral person," she told reporters.
The BBC's Waliur Rahman in Dhaka says the comments can be taken as an implicit acceptance of the appointment.
Violent protests began in Bangladesh on Friday after the opposition objected to the nomination of ex-Chief Justice KM Hasan to head the interim administration.
The Awami League accused him of being a stooge of the government, sent supporters on to the streets and threatened to paralyse the country.
On Saturday Mr Hasan pulled out just before he was due to be sworn in.
The president urged parties to find a replacement by Sunday afternoon.
Mr Ahmed then held separate talks with party leaders, but failed to reach agreement on a compromise candidate.
Under Bangladesh's unique system, when an administration comes to the end of its term it hands over to an unelected interim government which has 90 days to organise elections.
The opposition has been demanding a say in choosing the chief adviser.
Correspondents say Bangladeshi politics is especially bitter because of the personal rivalry between Ms Hasina Mrs Zia.
They have led the country in alternate terms since 1991 but have not spoken for years.
Parliament has been boycotted regularly by whichever party is in opposition, and a culture of street demonstrations has developed.