PESHAWAR (APP) - The Security Forces backed by gunship helicopters and artillery have killed 13 more militants and injured another nine in periodic clashes occurred in various areas of militancy-hit Swat Valley during the last 24 hours, a security official said on Sunday. "During the last 24 hours, at least 13 militants were killed and nine sustained critical injuries while two security personnel embraced Shahadat in the skirmishes occurred in different areas of restive Swat Valley," a Spokesman of Information Media Centre (IMC) Swat told this news agency. Four militants were killed and as many injured during a shootout with troops at Matta Tehsil between Saturday and Sunday night, he said. The miscreants attacked a patrolling party of security forces, which was retaliated, he said, adding two security personnel were martyred in the attack. The other incident occurred in Kabal Tehsil when the miscreants fired two rockets on the security forces' camp between Saturday and Sunday night, the spokesman said and added that the troops returned the fire, killing four militants and injuring two others at the spot. A vehicle of militants' fitted with mortars and rockets shells from which the rockets were fired on security camp were also destroyed, the spokesman said, adding that security forces were safe in the incident.  The IMC spokesman said that troops after receiving information about presence of hardened militants at Sardara and Shamozai area, pounded their suspected hideouts and bunkers and killed five of them while three sustained wounds. When asked about clashes in Wanai and Sir Banda areas, the Spokesman said the shootout was reported from these areas, however no casualty has been reported.