Islamabad, Feb 14 : Four terrorists were killed in a terror attack on security forces in Pakistan's Khyber Pakhtunkhwa province, the Counter Terrorism Department (CTD) of police said on Tuesday. According to the CTD statement, the terrorists late Monday night attacked a security forces vehicle, which was transporting accused terrorists at Mir Ali bypass area of the district, Xinhua News Agency reported. During an exchange of fire, four attackers were killed by the security forces while three other accused terrorists in the vehicle were killed by the terrorists' firing, the statement said. Around five to six attackers managed to flee the site by taking advantage of the darkness, it added. The killed attackers were identified as terrorists associated with the banned outfit Tehrik-e-Taliban Pakistan (TTP), the CTD said, adding that three of them were wanted by the CTD in allegedly several terrorist activities. A heavy contingent of security forces reached the site and carried out a search and clearance operation in the area, according to the statement. /IANS