New surveillance footage, released to Kenyan TV channels a week after the horrific mall siege, contradicts claims that 10 to 15 militants participated in the attack.

Four young men stroll through the besieged Westgate mall in Nairobi with Kalashnikovs slung across their shoulders. They chat on their phones, browse the aisles at the Nakumatt supermarket, and explore an electronics warehouse.

New surveillance footage, released to Kenyan TV channels a week after the horrific mall siege that that left at least 62 dead and hundreds injured, contradicts claims that 10 to 15 militants participated in the attack and raises fresh questions about the competence of the Kenyan response.

The footage, Kenyan authorities claim, has led them to identify four of the militants as Khattab al-Kene, Abu Baara al-Sudani, Omar Nabhan and Umayr. This information could not be confirmed independently.

Al-Shabab, a Somali militant group affiliated to al-Qaeda, took responsibility for the attack, describing the assault as retaliation for Kenyan military deployment in Somalia.

Little is know of the Westgate attackers. Matt Bryden, a former head of the U.N. Monitoring Group on Somalia, told the Associated Press that al-Kene and Umayr were known members of al-Hijra, a Kenyan extremist outfit related to Al-Shabab.

Omar Nabhan is a Mombasa-born al-Qaeda operative, according to Kenyan authorities. Mr. Bryden said Omar Nabhan could be a relative of Saleh Ali Saleh Nabhan, a known al-Qaeda operative accused of conducting multiple attacks in Kenya, including attacks on American embassies in Kenya and Tanzania in 1998.

In 2009, U.S. authorities had claimed to have killed Saleh Ali Saleh in a daylight raid in the south Somalia town of Baraawe.

On Saturday morning, news agencies in Mogadishu reported that unidentified foreign security forces had conducted a pre-dawn raid in Baraawe once more and had targeted a two-storey building allegedly used by al-Shabab.

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