LAHORE Unidentified gunmen fired shots at the office of PTI situated at Outfall Road in the provincial capital on Monday damaging some window panes of the office, while PTI activists escaped the attack unhurt. Confirming the attack on party office,PTI Punjab general secretaryDr Yasmin Rashid said elements fearing the growing popularity of the PTI after its successful October 30 moot could be involved in the harassing incident. However, she added that PTI activists could not be deterred from continuing their struggle under the leadership of Imran Khan for bringing a change in the country. The police authorities, denying the firing incident at PTI office at Outfall Road, said the investigations were underway.