Azerbaijan's most prominent human rights campaigner has been detained with her husband while trying to leave the country.
Leyla Yunus and her husband Arif Yunus, an academic, were hoping to board a flight from the capital Baku to Doha in Qatar, but were held at the airport.
They were released after a night in custody. But her passport was withheld.
Her arrest comes amid a crackdown on human rights activists and journalists in the oil-rich ex-Soviet state.
Azerbaijan has been ruled by the Aliyev family since 1993, soon after the break-up of the Soviet Union.
Mrs Yunus had been pressing for reconciliation between Azerbaijan and its next-door neighbour and bitter rival Armenia.
Earlier this month journalist Rauf Mirkadyrov, who worked with her on the Armenian project, was arrested and accused of spying for Armenia.
Mrs Yunus predicted last week that she faced imminent arrest.
On Tuesday morning, after her overnight detention, she was taken back to her home but refused to let police search it without a warrant. Amid the tension her husband fell ill and was taken to hospital.
Doctors told the BBC Azeri service he had suffered from hypertension and was stable.
'Like the Middle Ages'
Mrs Yunus told journalists outside her house that during her 11-hour detention she was not allowed to use the toilet, and when finally allowed to go it was only in the presence of a male police officer.
"It's like torture, like the Middle Ages," she said. "I haven't slept for a whole day."
She was later released, but her office was searched.
Azerbaijan has been repeatedly criticised by human rights organisations for stifling dissent, jailing opponents and obstructing democracy.
Nevertheless, it is preparing to assume the chairmanship of the council of ministers of the Council of Europe, Europe's top human rights body.
Ilham Aliyev was elected for a third term as president in October, though he did not even run a campaign, in a vote opponents said was undemocratic and fraudulent. Azerbaijan said the vote was fair.