Kenya mall attack group al-Shabaab threatens ‘long-lasting war, blood, destruction’

How big a threat is al Shabaab? 3:24

NAIROBI, Kenya - The leader of the al Qaeda-lined militant group behind the massacre of at least 72 people at a shopping mall has threatened Kenya with “long-lasting war, blood, destruction” over its peacekeeping role in neighboring Somalia.

Ahmed Godane, who is also known as Mukhtar Abu al-Zubayr, confirmed that his al Shabaab network was behind Saturday’s armed rampage and hostage siege at the Westgate complex in Nairobi, Reuters reported.

His threat, posted in an online message late Wednesday, came as more burial services were held for victims of the attack.

Two of the funerals – one Hindu and the other Muslim – were expected to be held side-by-side Thursday, underlining the international nature of the atrocity.

FBI investigating Kenya mall attack, officials say 2:25

Several Americans were injured in the attack, but a U.S. intelligence official told NBC News on Thursday there is "absolutely no confirmation" that U.S. citizens were among the perpetrators.

A number of names provided by Al Shabaab have been investigated, but so far those names have not turned up to be connected with a real person, the official said.

At the mall on Thursday, two blasts and a fireball were seen, attributed by investigators to bomb experts clearing out explosives left by the attackers.

House Intelligence Committee Chairman Mike Rogers said the mall assault showed al Shabaab has a "concerning ability" to strike outside its base of Somalia and stage a sophisticated, multilayered attack. 

The Michigan Republican, who has been briefed by U.S. intelligence officials, said the "bold attack" bore "striking similarities" with al Qaeda's deadly multi-day siege of an Algerian natural gas facility in January, according to The Associated Press.

He said the tactics used - including hostage-taking, multiple gunmen and small explosives and setting fires to cause panic - indicated the attackers planned the operation well in advance and had studied their target for the best time to strike.

Two Kenyan police officers were killed when al Shabaab militants attacked a security post inside Kenya near the Somali border early Thursday, The Associated Press reported.

Meanwhile, Somalia's defense minister said his government was struggling to fight al-Shabaab, and make an international plea for help in the form of weapons.

"We are not looking at jet fighters. It’s small arms," Abdulhakim Haji Faqi told NBC News. "We need the funding and resources."

He warned that the attack on the Westgate mall should be a wake-up call illustrating that Somalia-based terror organization al Shabaab was now a “global problem.”

“We need to defeat them ideologically and militarily," Faqi said. "If we had more weapons, they would be less of a problem by now. ... The way to help is to fund the Somali government."

In an interview with Britain's Channel 4 News on Wednesday, Somali President Hassan Sheikh Mohamud echoed Faqi's comments.

He said al Shabaab controlled "small parts" of the country which were being used as a "bomb factory" as well as for training and to "brainwash" young Somalis.

The United States, Israel, Britain and Canada are among the countries helping Kenyan authorities identify those involved in the Nairobi attack responsible for the four-day attack, Kenya’s interior minister Joseph Ole Lenku told reporters.

The FBI was on the scene soon after the attack and another contingent, including the Evidence Response Team and bomb technicians, is ready to fly to Kenya, officials said.

Forensic investigators were also due to begin a second day of searching through the rubble of the mall for clues - and more bodies. 

Since the mall attack, one or two additional U.S. Marine guards have been sent Nairobi to provide security at the U.S. Embassy, military officials told NBC News. According to officials that brings the total number of Marines there to "less than 20."

Alastair Jamieson reported from London. Jim Miklaszewski and Jeff Black of NBC as well as the Associated Press and Reuters contributed to this report.