By Zohra Bensemra and Diadie Ba

DAKAR - Riot police fired tear gas outside Senegal's National Assembly on Monday as crowds tried to gather to protest the postponement of the Feb. 25 presidential election, a move that caused anger and unrest over the weekend.

Lawmakers are set to debate a bill in parliament that would reschedule the election for Aug. 25 and extend President Macky Sall's mandate until his successor is installed.

Senegal has never postponed a presidential election, and Sall's announcement on Saturday pitched the West African nation into uncharted constitutional waters that threaten to further tarnish its reputation has a bastion of democratic stability in a region swept by coups.

The African Union on Monday joined a chorus of calls from regional bodies and Western governments for a new election date to be set as soon as possible.

Outside parliament, armoured police fired tear gas in an attempt to disperse around 100 people who had gathered to protest. They also made arrests, Reuters reporters said.

A widespread public outcry over the postponement has raised concerns the country will face violent protests like those that have intermittently broken out over concerns Sall would run for a third term and the alleged political sidelining of opposition leader Ousmane Sonko.

Sall said he delayed the election due to a dispute over the candidate list and alleged corruption within the constitutional body that handled the list.

Several prominent opposition figures, including Sonko, were barred from running for president, stoking discontent about the election process.

But there has been strong pushback against the delay, which some opposition and civil society groups have called an "institutional coup". Some contenders have said they would still push ahead with campaigns meant to kick off over the weekend. Others have vowed to challenge the postponement in court.

At least two female presidential candidates were detained when police in riot gear broke up protests in the capital Dakar on Sunday, firing tear gas and rounding up participants.

The authorities also took local television channel Walf off air on Sunday and revoked its licence, Walf said in a statement.

Senegal's sovereign dollar bonds fell on Monday, with its 2023 bond dropping to its lowest level in more than two months, according to Tradeweb data.

Barclays warned against downplaying the risk of clashes between the opposition and security forces and said the election delay could lead to further democratic backsliding.

"Such a postponement could open the door for subsequent postponements and allow the president to do many things," it said in a note.