​A terror cell allegedly conspiring to attack police buildings and a naval base in Sydney were found with a notepad full of scribbled plans, mobile phone photos of foreign fighters and an Islamic flag secreted in a family home.

Mohamed Rashad Almaouie, 20, and Abdullah Salihy, 24, were arrested on Wednesday, bringing to seven the number of men charged over the partially formed plot.

Mohamed Almaouie is arrested by police. Credit:Police Media

The group's arrest centred around a cache of notes, hand-written on A4 pages of a lined notebook, seized from the home of outspoken extremist Sulayman Khalid during raids in December 2014.

Police allege all seven, including a 15-year-old boy, played some part in authoring the notes, which listed the Australia Federal Police headquarters and NSW Police buildings as possible attack targets and made mention of "guerilla warfare" in the Blue Mountains.