A failed attempt by the Ukrainian security forces to push protesters from the centre of Kiev has weakened President Viktor Yanukovych and scotched any chance of a rapid end to the three-week crisis, analysts said.
Analysts said it was still a mystery as to why the authorities had made the "irrational" decision to send thousands of police into Independence Square in the early hours of Wednesday but it could not be ruled out the move was encouraged by Russia.
The attempt to retake Independence Square ended in a humiliating retreat by the authorities, who ended up being outnumbered as protesters streamed to the area in even greater numbers despite numbing cold and darkness.
Opposition leaders including jailed ex-prime minister Yulia Tymoshenko and the world boxing champion Vitali Klitschko made clear after the raid on the protest camp that there could now be no possibility of negotiations with Yanukovych to end the crisis.
"It is possible that the authorities were working on behalf of Russian interests," said Volodymyr Fesenko, director of the Penta think tank.
"But it also could be that the authorities were dizzy with success" after a similar move to budge protesters from outside government buildings earlier in the week proved successful, he said.
"But the authorities overestimated their capacities and underestimated the possibilities of the protesters. And now we are even further from a solution to the crisis, which has strengthened," he added.
The timing of the move by riot police and elite interior ministry troops was even more bewildering since it came at the very moment that EU foreign policy chief Catherine Ashton and US Assistant Secretary of State Victoria Nuland were in Kiev for talks with the president.
Ashton and Nuland have both made no secret of their sympathy for the protesters, who have taken to the streets for the last three weeks in anger at the government's decision to ditch a pact with the EU under Russian pressure.
Both senior diplomats have visited the protesters on Independence Square -- known in Kiev as the Maidan -- where in a likely unusual experience for them they were greeted as heroes.
'Yanukovych would understand he is next'
Olexiy Haran, professor at the Kiev Mohyla University, said popular anger at the bungled crackdown risked inciting even more people to take to the streets against Yanukovych.
"From the political point of view this seems unadvantageous for the authorities. Such actions, taken at night, cause tension and bring people out onto the street."
"It looks irrational. It could be a scenario written in the Kremlin," he said.
Yanukovych vowed late Wednesday that the authorities would never use force against peaceful protests and urged the opposition to sit down for talks.
But Klitschko upped the stakes after the attempted crackdown by saying "we need to demand the resignation not just of the government but of the president."
In a sign of the boiling tensions, Tymoshenko said: "I am calling on all Ukrainians: rise up! No talks with the gang."
Yuriy Yakymenko, deputy director of the Razumkov Centre think tank in Kiev, said that the authorities may have hoped to regain control of the situation by force.
"The path to solving the crisis lies through negotiations and snap parliamentary and presidential elections," he added.
Another option could be international pressure on Yanukovych, something the US State Department alluded to on Wednesday with a threat of sanctions.
"There have been many symbolic gestures on the part of the West but these authorities, it seems, will only understand the language of force," said Haran.
"Targeted sanctions are already overdue," he said, saying these could target officials such as national security chief Andriy Klyuyev and prosecutor general Viktor Pshonka.
"Then perhaps Yanukovych would understand that he could be the next and it could affect him and his family," he said.