© ReutersIn 2012, women from the north of Sudan and from South Sudan wait for public transport in Khartoum.
Fines for wearing trousers and the threat of beatings are being handed to women in Sudan "like traffic wardens issuing parking tickets", say the authors of a study on the country's controversial public order regime.
Researchers who carried out detailed interviews with 40 women who had fallen foul of the country's discriminatory laws found corrupt officials are increasingly using the threat of flogging to elicit money.
The majority of those jailed or beaten are marginalised women from low-income backgrounds or poor migrants who resort to the illegal practice of selling alcohol to feed their families, the report found.
Interviewees describe long spells in jail and beatings for "offences" such as wearing trousers, which are considered "indecent dress".
Earlier this month a Sudanese court dropped charges against a group of women who were caught wearing trousers at a party. If convicted they could have faced 40 lashes and a fine.
But often women face trial without legal assistance at spontaneous courts where their fate is determined at the whim of judges, according to the study.
"In terms of persecuting women for their clothing - it's a huge issue. Public order laws are used against women whom the authorities want to silence, including human rights defenders and students," said Carla Ferstman, who co-authored the report.
"There are economic incentives for maintaining this system because of the high fines. You have huge numbers of people hauled before the courts who will pay to avoid the lashings.
"It's like in the UK you have traffic wardens walking around looking for drivers who have parked in the wrong spot. This is being done in the same way to fuel certain budgets."
Raids are frequently carried out where police force their way into private homes in search of alcohol, the study found, or to arrest individuals for inappropriate behaviour or dress.
One interviewee told researchers: "Police officers climb over walls and invade houses with no respect for privacy. We are psychologically traumatised by the raids and the inhumane treatment we face."
Female alcohol and tea sellers, students and activists, former detainees and prisoners in Khartoum State were interviewed between August and December 2016 for the study, Criminalisation of women in Sudan: a need for fundamental reform.
Prison staff and members of the judiciary, the legal profession and ministry of justice were also interviewed for the joint publication by the Strategic Initiative for Women in the Horn of Africa (Siha) and the Redress Trust.
The report concludes that Sudan's public order rules, which enforce strict moral codes, have been further extended and continue to be used in an arbitrary manner to oppress women.
"We are calling for these laws to be abolished. The atmosphere they create is one of fear and self-censorship as women are never aware of when or for what reason they might be arrested," said Ferstman, the director of Redress.
More than 70% of all public order cases involve women, according to a recent survey by Sajeenat, an advocacy group which focuses on the rights of female prisoners in Sudan. In 60% of these cases the punishment came in the form of a hefty fine.
Those who cannot afford to pay face lashings or imprisonment, which can lead to further abuses while in detention both by guards and other prisoners.
Nahla, a university student, was fined 2,000 Sudanese pounds (£225) for consuming shisha and 5,000 Sudanese pounds for wearing trousers. Because she was unable to pay immediately she was also lashed 20 times and spent time in prison.
Terrified of how her family would react, she borrowed money from elsewhere to settle the fine. She was released but must now balance her studies with part-time work to repay the loan.
Other women jailed are often poor migrants operating in the illegal trade of alcohol brewing as the only way to make a living. They find themselves in a vicious cycle when landed in prison with no way of paying the fine.
One interviewee said: "The judge sentenced me to pay 4,000 Sudanese pounds or face six months' imprisonment.
"I have no money and I'm the only earner in my family. I have six children . Selling alcohol is my only income. I applied for a mercy and the fine, which was reduced to 2,000 Sudanese pounds, was paid by my neighbours."
The public order courts have been rapidly expanding since South Sudan seceded in 2011 and Khartoum looked to new ways of raising funds after losing 75% of its oil revenues.
There are now 22 public order courts in Khartoum and one in almost every town across Sudan.
The investigation by members of Ayin, a Khartoum-based media group, found that these courts in Sudan earn $1.8m a month, a figure equivalent to £1.3m and worked out using Sudan's Central Bank 2016 exchange rate.
Lutz Oette, director at the Centre for Human Rights Law at London's School of Oriental and African Studies, said: "The use of public order laws as a tool of social control and discrimination has been so pernicious that the whole system needs a fundamental overhaul.
"The repeal of the relevant law and provisions forms an important part of the overdue reforms Sudan must take to guarantee women's rights."
Campaigners say it is important for foreign governments to understand the full picture of what is happening in Sudan after several years without any progress on the issue even despite several high profile cases.
"Any UK engagement with Sudan should insist on a speedy repeal of these laws to end such legally sanctioned discrimination, including the practice of flogging, once and for all," said Oette.