NEW : Pakistani Taliban takes credit for attack . Army Mission : Militants strike government troops in northwest Pakistan . 17 suspected militants died , but escape after long battle , spokesman says . Pakistani Taliban says it 's joining forces with fellow militant group Lashkar - i - Taliban .
NEW : Pakistani Taliban takes credit for attack . Army spokesman : Militants strike government troops in northwest Pakistan . 17 suspected militants died , others escape after long battle , spokesman says . Pakistani Taliban says it 's joining forces with fellow militant group Lashkar-i-Islam .