SWABI - At least 12 people were wounded in an attack on a police van at a PTI public meeting venue, minutes after Imran Khan left the place telling attendants they will shoot US drones down if voted to power.The attackers lobbed two hand grenades and opened fired at the vehicle of policemen - performing guard duty at Pakistan Tehreek-i-Insaf (PTI) meeting in Shewa playground here on Friday - injuring seven policemen and five others.Earlier, in his address Imran Khan said the rulers should be ashamed at their inability to get stopped the unending drone attacks on Pakistani soil that are killing innocent people, besides violating country’s sovereignty. “We will help Americans get out of Afghanistan but will not become part of their war,” Imran said as he vowed that PTI will not let US continue attacking Pakistan and will shoot their drones down. He also pledged that PTI will free the people of Pakistan from US slavery if it comes to power. “We won’t beg, we won’t take loans and will generate our own funds.”Declaring the success of his party as imminent, the cricketer-turned-politician said even if all political parties join hands to defeat PTI, they will miserably fail. “Even if PML-N (Pakistan Muslim League-Nawaz), PPP (Pakistan Peoples Party) and JUI-F (Jamiat Ulema Islam-Fazal) unite, PTI will bowl them all out on the first ball.”The nation has decided to go far the change and no political force can stop the PTI’s tsunami, which is sweeping the country and has already shaken the country’s political heavyweights and ruling elites, he pronounced. Imran dubbed his party’s massive rallies in Karachi and Lahore as the starting points of the PTI’s political tsunami. “This (tsunami) cannot be stopped by the corrupt politicians who have failed to deliver and plunged the country into an abyss of multiple crises, he went on.Promising a better future for the country under his party’s government, Imran said PTI will bring investment to the country and will tax the rich. “We want our country to be economically stable and politically mature,” he said and presented a promising scenario, saying, “Green passport will be respected and people from abroad will come to Pakistan in search of jobs,” Imran said. He also promised to fix the education sector and put in place a uniform education system.Earlier, Imran Khan entered the public meeting in a big procession and as he reached the main stage there were deafening slogans ‘Imran Khan Zindabad’, ‘Tehreek-i-Insaaf Zindabad’. Mr Khan waved to the crowd with a big smile and the crowd cheered. Wearing shalwar kameez (the traditional dress of the country) and a black coat, Imran sat on the stage with other party leaders including Javed Hashmi, Asad Qaisar and Khawaja Muhammad Hoti. On this occasion, several leaders of different political parties announced to join the PTI caravan.Due to great rush Imran’s reaching to the stage was delayed for more than two hours. The ground where the public meeting was held was jammed-packed and a number of people amassed on the Shewa Bridge and the roads leading to the venue of the meeting.Swabi district has been a stronghold of the Awami National Party for the last six decades and the red shirt leaders won majority of the national and provincial assembly seats from the district in the in 2008 elections.