The most prominent banned "mazhabi tanzeem" in Lahore is the Lashkar-e-Tayba/Jamaat-ud-Dawa outfit. Some other reporters were hinting at attackers being from Southern Punjab, which indicates involvement of Lashkar-e-Jhangvi, which is of course known to be close to TTP and Al Qaeda.
no it seems its lashkare jhangvi or it can be an attempt by LET to hijack bus and ask for release of lakhvi suspect in mumbai terrorist raid. .