Sudanese protester Walid Abdelrahim was shot dead last month in Khartoum but for his mother he is still alive -- thanks to a colourful mural of his smiling face on a wall of their home.

The portrait is part of a campaign launched by Sudanese artist Assil Diab to draw murals and graffiti to commemorate demonstrators killed in the months-old protest movement that has rocked the northeast African country.

These murals are specifically drawn on the walls of protesters' own homes or in their neighbourhoods.

'Immortalise their legacy'

Diab, a former employee of Doha-based Al-Jazeera television network, and her team got their motivation from a protest catchcry: "Our martyrs didn't die, they are alive among the revolutionaries!"

"Graffiti makes martyrs come alive and reminds people of them even if the people themselves did or did not support the revolution."

For years such artwork remained underground amid censorship imposed by heavy-handed security agents of Bashir's regime, who considered it anti-establishment or pure vandalism.

'Dangerous experience'

A student in Britain, Mattar was back to visit family and had just celebrated his 26th birthday when he decided to spend a night with the demonstrators at the sit-in.

Sudanese artist Asil Diab, walks in front of a mural painting of Mohamed Mattar.

His death in the raid had evoked a campaign of solidarity on social media under the hashtag #blueformattar.

Some of the paintings Diab has drawn are also of protesters killed in a September 2013 crackdown on anti-austerity rallies.

They include Babikir Anwar whose face Diab has drawn on a wall of his family's home in the neighbourhood of Shambat.

"We will not forget you Bakur," is written below the painting, referring to his nickname.

Agence France-Presse