Supporters of opposition presidential election candidate Bassirou Diomaye Faye called for his release and that of opposition figure Ousmane Sonko on Sunday, citing the need for "equal treatment" under the constitution.
Several government opponents were released from prison last Thursday following an order by President Macky Sall.
However, the two key opposition figures were not among those freed as the country faces uncertainty over delayed presidential elections.
"All candidates must benefit from the constitutional principles of equal treatment," said a statement from the Diomaye-President coalition.
"That's why the release without delay of candidate Bassirou Diomaye Diakhar Faye is a popular demand and respectful of the Constitution," the statement said.
Stand-off over election
The Constitutional Court rejected Sonko's candidacy for the presidential elections but accepted that of Faye, the PASTEF's party's number two. In all, twenty 20 candidates had been cleared for the elections.
Ousmane Sonko has been in prison since April 2023 for "contempt of court" and "defamation against a corporate body" over a Facebook post.
Sonko, who came third in the 2019 presidential election, has been at the centre of a standoff with the state that has lasted more than two years and sparked often deadly unrest.
The Constitutional Council rejected Sonko's candidature due to his six-month suspended sentence for defamation, which was upheld by the Supreme Court on January 4.
Senegal was then rocked by protests after President Sall postponed the February 25 elections to choose his successor just a day before campaigning was due to start two weeks ago. The incumbent president's term in office is due to end on April 2.
Senegal's parliament had approved the postponement but the Constitutional Court ruled on Thursday that the delay was unconstitutional.
President Sall has agreed to organise elections ''as soon as possible'' in line with the court ruling. However, he hasn't announced a date yet.
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