NAIROBI, Kenya – Soon after gunmen stormed a Kenyan shopping mall on Saturday, killing dozens in a spray of bullets and grenades, triumphant tweets swept the Internet.

“The Mujahideen entered Westgate Mall today at around noon and are still inside the mall, fighting the Kenyan Kuffar inside their own turf,” cheered the Twitter account of al-Shabab, al-Qaida’s affiliate in Somalia. “The Mujahideen inside the mall confirmed to @HSM — Press that they killed over 100 Kenyan kuffar & battle is ongoing.”

Hours later, the account disappeared. For the third time this year, Twitter tried to kick al-Shabab off its social media platform. Within hours, a new account popped up once again, tweeting mocking jibes at Kenyans as if it had never stopped. Then it too went silent.

As the horror of the assault on Nairobi’s Westgate mall spun unresolved through a second day Sunday, with the death toll rising and uncertainty surrounding what was taking place at the multistory complex, the Internet became the only way to learn the motivations of the attackers — amid fierce debate over whether terrorists should have their own platform.

“The al-Shabab terror group has claimed responsibility for this cowardly act of terror on social media. However, investigations are underway to conclusively establish those responsible for this mayhem,” President Uhuru Kenyatta of Kenya said in a televised statement.