Yesterday’s protests saw the arrest of many protesters from the streets by police and National Intelligence Security Service (NISS) agents. Among them is prominent Sudanese Twitter personality and activist Usamah Mohammed Ali (@simsimt ).
In his last tweet , Usamah was advocating free content to help spread the word about the events happening on the streets in the capital Khartoum:
Btw, I'm just being technical. You can use my tweets without even mentioning me. Free content advocate here!
Usamah’s last couple of tweets included information about his whereabouts and the situation on the ground. He was in Burri  area next to Nile Street [ar]:
في بري الشريف. عدد كبير من بكاسي الاحتياط والأمن ودفارات الشرطة والأهالي بأعداد متفرقة واقفين.
In Burri al-Sharif. Large number of security and police trucks and residents in wide numbers standing.
where he said there was a lot of security presence, and arrests taking place:
الأمنجية أعدادهم كبيرة ومتمركزين في أكتر من بوكسي. في بحري الشفناهم كانو مسلحين. أفتكر كلهم بكونو كدة.
There's a large number of NISS agents and they're centered at more than one truck. In Khartoum North, the ones we saw were armed. I think they are all like that.
He tweeted a photograph  of arrests being made by security personnel, moments before getting arrested himself.
بوكسي الأمن دة وقف العربية السيلفر الواقفة وراو وطلعو منها زول وركبو معاهم. العربية فيها أولاد وبنات.
This NISS truck intercepted the silver car parked behind it and dragged someone out of it. They took him with them to their car. The car is filled with boys and girls.
@Arch_Asaad  عشان بس لو حصلت اي حاجة.
I'm with Asaad, just in case anything happens to me.
Asaad tweeted  as soon he was released that he didn’t know the whereabouts of Usamah.
@simsimt  is not released yet! And I don't know where is he!!
According to Asaad, Usamah was taken to NISS headquarters in Khartoum North while he himself was taken to a police station in Khartoum.
Usamah’s friends were tweeting their concern for his safety and demanding his immediate release. Ayman Elkhidir showed  his concern for Usamah,
Montaga Elameen demanded  people spread the word about all the people detained at the protests:
Egyptian Mohammed Al Dahshan, a journalist, writer and a personal friend of Usamah’s, was also concerned for his safety, tweeting :
Earlier that day, Usamah recorded a video  for Al Jazeera’s The Stream highlighting his reasons for going to the street on the 30th of June 2012 – the planned protest date, and the 23rd anniversary of the Sudan’s current ruling National Congress Party.
Several other Sudanese Twitter users have been arrested and released, such as Omer Mahgoub (@OmarMahgoub), who was released today. He was held in the same building as Usamah, but says he has not seen him.
Usamah has been in the custody of the notorious NISS for over 24 hours, and his twitter friends are campaigning for him using #FreeUsamah.
In the wake of the ongoing protests taking place in Khartoum and other states calling on the fall of the regime, numerous other peaceful protesters have been kidnapped by the NISS and many of them were tortured.