The government is tracking the finances of people suspected of ties to Al-Shabaab, the militant group that claimed responsibility for the Thursday attack.
So far, the government has frozen 86 accounts, but that number could go up, said Mwenda Njoka, a spokesman for the Interior Ministry.
The government has tracked supporters of the terror group since 2011, and efforts to freeze their assets have gone on since then. It has a list of suspects from various parts of the country, but mostly in Nairobi and Mombasa, he said.
Kenyans mourned the victims of the attack Tuesday night at Nairobi's Uhuru Park, where hundreds gathered.
Organizers unloaded 147 crosses, some draped with the nation's flag, as candles flickered in the dark.
Of the fatalities, 142 were students at the university, and the rest were security forces and campus security.
"I can't even look at pictures of the people killed without crying," said Mary Wambui, 32, who lives in Nakuru, hundreds of miles from Garissa.
"They were just children. They were trying to make a better life for themselves. Some were first to go to college in their communities. They died trying to get an education."
Using the hashtag #147notjustanumber, Kenyans used social media to talk about the lives of the victims.
They shared pictures of beaming faces, full of life and energy, in happier days. They talked about parents too shocked to speak after identifying their children's bodies.
Some students remain unaccounted for, and wailing relatives alternate their searches between hospitals and morgues. Kenyan authorities have not released the names of the victims.
Kenyan authorities had prior intelligence that a university in Garissa could be attacked, yet the country's rapid response team was stuck in Nairobi for hours after the massacre awaiting transport, a police source said Monday.
The frozen accounts is the latest in a series of actions as the government faced heavy criticism for the siege, which lasted hours.
A spokesman for President Uhuru Kenyatta said authorities "got the job done" and saved lives. The university had about 800 students.
"With the benefit of hindsight, you can always say things could have been done better," Manoah Esipisu said.
Kenya also launched airstrikes Monday targeting Al-Shabaab's training camps in Somalia
, according to a military source, who said they were not retaliation for last week's massacre.
"The latest attack of Al-Shabaab bases by the Kenya military is part of the ongoing operations that started in 2011," the source said Monday.
Kenya has also offered 20 million Kenyan shillings, or about $215,000, for information on the whereabouts of Mohamed Mohamud, who allegedly organized the attack.
Mohamud is a senior Al-Shabaab leader known by the aliases Dulyadin and Gamadhere, authorities said.
Al-Shabaab is based in Somalia, and its violence has spread to Kenya before. In 2013, militants attacked Nairobi's upscale Westgate Mall
, leaving 67 people dead.
The terror group has intensified attacks in Kenya since the country sent troops to Somalia four years ago to help battle the militants.