Complex sentence: The Anti-Terrorist Branch (at that time called the Bomb Squad) originally dealt with bombings perpetrated by anarchist groups, during the 1970s it assisted in the campaign against the IRA, alongside Special Branch and the Security Service (MI5).
Split into simpler sentences: The Anti-Terrorist Branch (at that time called the Bomb Squad) originally dealt with bombings perpetrated by anarchist groups. During the 1970s it assisted in the campaign against the IRA, alongside Special Branch and the Security Service (MI5).