Four young men and a teenager who prepared for a terrorist act that involved killing police officers and targeting government buildings in Sydney have been jailed.

Sulayman Khalid, 22, Jibryl Almaouie, 24, and the teen previously pleaded guilty to conspiring to do acts in preparation for a terrorist act to advance “violent jihad” in late 2014.

Co-offenders Mohamed Almaouie, 22, and Farhad Said, 25, previously pleaded guilty to the lesser charge of knowingly making a document likely to facilitate a terrorist act.

Supporters broke down in tears as Justice Geoffrey Bellew handed down their sentences in a NSW Supreme Court in Parramatta on Friday.

Khalid was described as a “devout terrorist” and the leader of the conspiracy plot by Justice Bellew, the ABC reported.

Justice Bellew said firearms and ammunition were acquired and there was nothing amateurish about what was planned, the ABC reported.

“[Khalid] was corrupted by a dangerous, violent and perverted ideology, to which he unequivocally subscribed, which he wore as a badge of honour, but has no place in a civilised society,” he told the court.

Khalid was sentenced to 22 years and six months with a non-parole period of 16 years and nine months. He will be eligible for parole in 2031.He made the one-fingered ISIS salute as he was led to the docks.

His sister shouted: “Sulayman, I love you”. His father said: “Stay strong.”

Jibryl Almaouie was sentenced to 18 years and six months in jail with a non-parole period of 14 years and two months.

The teenager was jailed for 13 years and six months with a non-parole period of 10 years and one month.

Mohamed Almaouie was sentenced to nine years’ jail with a non-parole period of six years and nine months.

Said was jailed for nine years and six months with a non-parole period of seven years and one month.

—AAP