Scotland Yard announced the arrests of  three more suspects in an ongoing terror investigation in the United Kingdom.
CNN  — 

Three more suspects were arrested Monday in central London in an ongoing terror investigation in the United Kingdom, Scotland Yard announced.

The men, who are between the ages of 21 and 25, were arrested on suspicion of being “concerned, preparation or instigation of acts of terrorism.”

Two of five men arrested last week were released from custody Monday, the Scotland Yard statement said, leaving six men in custody.

Authorities have searched a business in west London and will search four residences in northwest London, police said.

After last week’s arrests, a UK security source told CNN that authorities may have foiled a terror plot aimed at Britain in its early stages. Islamist terrorism was “the clear reason” for the plot, according to the source.

UK police arrest 5th suspect in alleged terror plot