The detention of the Zimbabwe's opposition leader for a third day has strengthened the party's will to press on with anti-government protests, the opposition deputy leader has said.
Gibson Sibanda, vice president of the Movement for Democratic Change, said unannounced protests would be called at short notice if Morgan Tsvangirai is not released.
"We won't give a deadline for his release for fear of pre-empting our strategies," he said.
Tsvangirai, arrested on Friday on treason charges after a week of strikes and protests that shut down much of the economy, is being held in police station in Harare.
Sibanda said Tsvangirai's arrest was aimed at provoking the party into violent action to create a pretext for the government to use force against activists and to outlaw the party.
But if Tsvangirai was not quickly freed, "the dying regime must brace itself for a long winter of intense but peaceful mass action," he said.
The times and venues of last week's street protests had been advertised, allowing troops and police to deploy in large numbers.
The next protests will not be announced in advance, Sibanda said.
Tsvangirai was brought to court on Saturday on treason charges that he called protests to overthrow President Robert Mugabe and his government. He is scheduled to reappear in court tomorrow.
The opposition will demand the charges, denied by Tsvangirai, be thrown out for lack of evidence.