Bukit Aman CID director Comm Datuk Huzir Mohamed (pic) said the gang members were arrested under Poca on Thursday (Nov 12).
"We believe the gang is responsible for the shooting in front of a school in Banting on Sept 25.
"They are active in Banting and Dengkil," he said in a statement on Friday (Nov 13).
The arrests were necessary to ensure safety and public order is preserved, he added.
"Our swoop began on Oct 13 and Oct 14, where 29 TCB 21 members were detained for organised crime offences.
"They were subsequently detained under Security Offences (Special Measures) Act 2012 (Sosma) for 28 days," Comm Huzir said.
The investigation papers were referred to the Attorney General's Chambers' serious crime division head but there were not enough statements to charge them under Section 130v of the Penal Code, he added.
"Our investigations revealed that this gang is active in attempted murder using firearms, robbery and rioting.
"They also believed to be responsible for various other crimes including arson, burning excavators, extortion and assault.
"Thus we detained 25 of them under Poca," he added.
On Sept 25, two men suffered multiple injuries after they were shot by two armed gunmen in front of a secondary school in Banting.
The victims, who were in a blue BMW, were fired upon by the gunmen in front of SMK Telok Datok in Banting at about 12.45pm.
Several students were also injured after the victims rammed into them and several cars in a bid to escape the attack.