British police arrested four Muslim men in Birmingham Tuesday for allegedly planning terror operations. They have since been charged with engaging in conduct in preparation of terrorist acts contrary to section 5(1) of the Terrorism Act 2006, a police spokesman said.

The four were remanded in custody by a judge at Westminster Magistrates Court.

The defendants are Khobaib Hussain, Ishaaq Hussain and Shahid Kasam Khan, all aged 19, and Naweed Mahmood Ali, 24. They are accused of fundraising for terrorist purposes and of undergoing terrorist training in Pakistan.

They were arrested at their homes in the Sparkhill area of Birmingham by officers from the West Midlands Counter Terrorism Unit on Tuesday. According to Sky News, West Midlands Police said the arrests were pre-planned and were made by unarmed officers as part of a major ongoing investigation.

“These charges are in connection with Operation Pitsford, a major counter terrorism investigation that has already seen eight people charged and appear in court,” the police spokesman said.