The United States embassy in Khartoum has destroyed the passports of Sudanese and other third country nationals who were in the process of applying for visas and passports there.
The move leaves those affected unable to leave Sudan, which has been in a state of turmoil since 15 April, when war broke out between the Sudanese army and the paramilitary Rapid Support Forces (RSF).
Alhaj Sharaf, a Sudanese software engineer, had been accepted into a master's degree programme in computer science at Maharishi International University in Fairfield, Iowa. He was supposed to start courses on 2 May.
In order to study in the US, Sharaf's passport had been submitted to the embassy in Khartoum for non-immigrant visa processing. The visa had already been issued when the fighting began, but the passport had not been returned.
Sharaf was at his family home in Khartoum North when the conflict broke out not far away. He moved to his cousin's home in Omdurman, Khartoum's twin city, because it was safer there.