Read the text. Use the verbs in brackets in the past simple or past continuous to complete the sentences:
LOCAL TERRORISTS AMBUSH ROUTINE PATROL
Four soldiers were injured yesterday because a bomb ________ (explode) near their armored vehicle. The incident _______ (happen) at 4.30 pm while the soldiers _______ (return) to base after a routine patrol. Their vehicle _______ (travel) along the High Street when suddenly they _______ (have) to slow down because a bomb which was hidden in a rubbish bin _______ (explode).