Kenya's counterterrorism police unit released closed-circuit television footage Sunday that showed two men entering a local bank where they collected money and paid for a car used to bring terrorists to Nairobi's Westgate Mall, indicating the deadly attack was planned weeks in advance, officials said.

Boniface Mwaniki, the head of Kenya's Anti-Terrorism Police Unit, said the men had gone to Barclays Bank on Sept. 6 and retrieved enough money to pay for the 340,000 shilling car (around $4,000). The Mitsubishi Lancer was found blocking the main entrance of the mall with two grenade pins inside, indicating the grenades had been thrown from inside the vehicle, Mwaniki said.

Several survivors of the attack, who were near the entrance of Westgate, said that the terrorists first lobbed grenades into the interior of the mall, a blast which caused the glass facade of a jewelry shop to shatter, stunning the unarmed guards, who abandoned their posts.

"If you know how a grenade works, you'd know that you remove the pin, and then you throw it (the grenade.) The pin gets dropped wherever you are," Mwaniki said, to explain how police used the location of the pin to identity the vehicle as the attackers' car.

Long after shoppers returned to the mall to retrieve their abandoned cars, the gray-colored Mitsubishi, with Plate No. KAS 575X remained unclaimed in front of the shopping center, he said.

The footage played for reporters on Sunday showed two men entering the Queensway branch of Barclays in Nairobi. One of the men is described as light-skinned, around 5-feet-8-inches tall and believed to be Kenyan of Somali origin, from Mandera, a town near the Kenya-Somali border, according to a statement. Police identified him as Abd Kadir Haret Muhamed, also known as Muhamed Hussen. They said that he spoke Swahili fluently, as well as Sheng.

The suspect is married to a Kenyan woman, Shurekha Hussen, who was recently arrested by police and helped investigators identify the second suspect, Mwaniki said.

The second man captured on camera is believed to be Somali, identified as Adan Dheq, also known as Hussen Abdi Ali as well as Abdulahi Dugon Subow, police said. He is 5-feet-5-inches tall, and speaks "broken" Swahili, according to the statement.

The newly released names come a day after Kenya's military spokesman identified four attackers, who were seen strolling through the mall, machine guns strapped to their bodies. It brings to six the number of suspects that have been identified so far for the Sept. 21 attack that left more than 60 people dead.

Mwaniki cautioned that the two suspects identified on Sunday may not have been inside the mall during the attack.

"We don't yet know. But it appears that these were the guys doing the logistics," he said.

The newly released footage also indicates that police are now honing in on the identities of the alleged terrorists, using DMV and insurance records, as well as data mined from financial transactions.

The attack on the Westgate Mall was claimed by the leader of al-Shabab, al-Qaida's affiliate in East Africa. Analysts had predicted that the attack could not have been carried out without the complicity of Kenyan nationals, and the identities of the alleged attackers revealed so far seems to support this conclusion.