In Pakistan, at least 18 militants were killed during a clash with security forces in the northwest of the country today. <br/><br/>Officials said the clashes took place as security forces conducted search operation in Orakzai tribal agency. <br/><br/>Four militants were arrested during the operation. <br/><br/>Reports say troops destroyed three hideouts of militants and recovered large quantity of arms and munitions. <br/><br/>A security man was also injured in the fighting. <br/>