An ISIS-linked terror group was planning to carry out "large-scale attacks" in Kenya comparable to the 2013 Westgate Mall siege that left dozens of people dead, local police said Wednesday.
Kenya's National Police Service said it had foiled a plot due to unfold last Friday that involved medical experts with plans to "unleash a biological attack in Kenya using anthrax."
A medical intern named Mohammed Abdi Ali was arrested under the country's terror laws in connection with the alleged plan, police added in a statement.
Ali, who was interning at a hospital in the south of the country, is accused of radicalizing and recruiting university students and other young people into "terrorism networks," the statement said.
Police added that Ali's wife, Nuseiba Mohammed Haji — a student at Uganda's Kampala International University — and her alleged "accomplice" Fatuma Mohammed Hanshi also were arrested in Uganda. The statement did not provide further details on their alleged involvement in any plot.
The arrests represented a "major breakthrough in the fight against terrorism in Kenya and the region," according to the police statement.
It said that since Ali's arrest, "his accomplices in the terror network in Kenya have gone into hiding to evade justice," naming two other suspects in Kenya as medical interns Ahmed Hish and Farah Dagane.
"The suspects were planning large-scale attacks akin to the Westgate Mall attack, with the intention of killing innocent Kenyans," police said. "[Ali's] network also included medical experts with whom they planned to unleash a biological attack in Kenya using anthrax."
Related: How Somalia's Al Shabab Grew Into a Global Terror Threat
Officials did not name the organization believed to be behind the alleged plot, referring to it only as an "East African terror group" with links to ISIS and neighboring Somalia that had been helping Kenyan youths leave the country and join militants in Libya and Syria.
The most well-known Islamist group in the region is the Somalia-based al Shabab, which has claimed numerous attacks on civilians, including a college attack in April 2015 that left at least 147 people dead, as well as the deadly Westgate siege itself.