Fresh Pakistan army troops arrive to take part in rescue operation at the site of Boeing 737 passenger plane crash on the outskirts of Islamabad, Pakistan, Saturday, April 21, 2012. Pakistan blocked ... more 
Fresh Pakistan army troops arrive to take part in rescue operation at the site of Boeing 737 passenger plane crash on the outskirts of Islamabad, Pakistan, Saturday, April 21, 2012. Pakistan blocked the head of an airline whose jet crashed near the capital from leaving the country as it began an investigation Saturday into the country's second major air disaster in less then two years. (AP Photo/Anjum Naveed) less 
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Associated Press | Photo By Anjum Naveed
Sat, Apr 21, 2012 5:25 AM EDT