(CNN)Anti-government protesters in Sudan faced a violent crackdown Tuesday in the capital of Khartoum, marking the seventh day of demonstrations that have rocked the northern African country.
Sudan cracks down on growing anti-government protests
The protesters -- organized by a group of professional unions including doctors, lawyers, teachers and students and supported by two of the largest opposition parties -- are calling for President Omar al-Bashir to step down.
The demonstrations began over fuel shortages and a spike in food prices that saw the cost of bread double in the past year.
But they soon evolved into a wider call for the controversial leader to resign.
Bashir, who was charged with crimes against humanity, including genocide, by the International Criminal Court related to the Darfur conflict in Sudan in 2010, has been President for almost three decades.
Sudan is oil-rich, but poverty is rife in the country, with many of Bashir's critics attributing its economic woes to widespread corruption.
Nearly 20% of the labor force is unemployed, according to recent International Monetary Fund data; inflation reportedly has soared to nearly 70%.
In videos, protesters can be seen chanting, "The people want to topple the regime," and "Freedom! Freedom," evoking memories of the 2011 Arab Spring uprising.
Security forces have sought to quash the protests by shooting live fire and tear gas into crowds of peaceful demonstrators, witnesses have told CNN.
At least 37 people have been killed since the protests began, according to Amnesty International, which has called for the immediate halt of the government's violence against protesters.
"The fact that the security forces are using lethal force so indiscriminately against unarmed protesters is extremely troubling," Sarah Jackson, Amnesty International's deputy director for East Africa, the Great Lakes and the Horn, said in a statement Monday.
At the demonstrations Tuesday in Khartoum, activist Ahmad Mahmoud told CNN that riot police had arri