Mariam Al-Mahdi and her sister Rabah were among those arrested earlier on Sunday
Sunday's procession was to start at the Umma Party's offices in the capital's twin city of Omdurman
President Bashir swept to power in an 1989 coup that had toppled the then government of Sadiq al-Mahdi
A Sudanese emergency court Sunday sentenced an opposition leader to a week in jail as police detained several people intent on marching on parliament to protest a state of emergency.
Mariam al-Mahdi -- daughter of opposition Umma Party chief and ex-prime minister Sadiq al-Mahdi - was sentenced to a week in prison by an emergency court, Mr Mohamed al-Mahdi, another of the party's leaders, told AFP.
Mariam Al-Mahdi and her sister Rabah were among those arrested earlier on Sunday.
Initial crackdown
Protest organisers had called for a march to challenge the state of emergency, imposed nationwide by President Omar al-Bashir on February 22.
President Bashir's move came after an initial crackdown on demonstrations that have taken place against his iron-fisted rule since December failed to rein in the protest movement.
The president has ordered a slew of tough measures to quell the demonstrations, including banning all unauthorised rallies and setting up special emergency courts to probe transgressions.
Sunday's procession was to start at the Umma Party's offices in the capital's twin city of Omdurman.
Security agents
"As some of our leaders came out of the party office to lead the march, security agents arrested them," said Mohamed al-Mahdi, who is not connected to the former premier's family.
President Bashir swept to power in an 1989 Islamist-backed coup that had toppled the then government of Sadiq al-Mahdi.
Alongside the two daughters of the former premier, "five other leaders of our party have also been taken away by security agents," Mr Mohamed al-Mahdi said.