Updated

A Sudanese opposition party says more than 10 opposition leaders have been arrested ahead of the latest day of protests urging President Omar al-Bashir to resign.

In a statement, the Sudanese Congress Party says security forces "pre-empted" demonstrations by arresting the deputy head of the Umma Party, Mariam Sadiq al-Mahdi; the party's Secretary-General Sara Naqdallah; Communist Party leader Mokhtar al-Khatib, and others.

Later, police fired tear gas to disperse hundreds who had gathered to march, near the Arab Market area in Khartoum.

Sudan has been rocked by a wave of protests since December calling on al-Bashir, who seized power in a 1989 military coup, to step down. Activists say at least 57 people have been killed, but the government tally stands at 30.