The widow of a radical Muslim preacher was charged on Friday of helping three other women attack a Kenyan police station.

In what the first incident in Kenya to be claimed by Islamic State, the women entered Mombasa's central police station on Sept. 11 under the pretext of reporting a stolen phone. They stabbed one officer and set fire to the building with a petrol bomb before they were all shot dead.

A Kenyan court charged Hania Said Sagar, widow of sheikh Aboud Rogo - a preacher accused of supporting and recruiting for Somali Islamist group al Shabaab - with withholding information that could have prevented the attack.

Rogo was killed by gunmen in 2012, sparking days of riots in Mombasa by supporters who accused the police of gunning him down, something the police denied.

Police said they had evidence that Sagar had communicated with the three women before they launched the attack. They also had evidence of a mobile phone money transfer between her and one of the attackers.

"You knew Tasmin Yakoub (one of the three attackers) who was the mastermind of a terror attack at central police station, you failed to disclose information which could have prevented a terror attack," the charge sheet read.

Sagar denied the charge and the court ordered she be held until Monday when it will rule on a bail application.

She faces up to 20 years in jail if convicted.

Kenya has been cracking down on people they accuse of promoting militant ideas or planning and carrying out attacks, particularly in the coast region, where many Muslims live in the majority Christian African nation.

Before the police station attack, Islamist attacks in Kenya have usually been claimed by Somalia's al Shabaab.