RAWALPINDI - In a deadly terrorist attack on Pakistan army headquarters (GHQ), four terrorists who launched the assault with sophisticated weapons were killed whereas six soldiers including two senior army officials were martyred here on Saturday. Later, some four to five terrorists also took some 10 to 15 security personnel hostage in a security office near check post No 2 near GHQ. Military officials said the attackers were surrounded, and efforts were being made to recover the hostages safely as the operation continued till the filing of this report. Security officials and some eyewitnesses told TheNation that some terrorists riding in a white coloured Suzuki carry-van bearing army number plate reached a check post near GHQ where army personnel engaged the assailants in camouflage gear after they tried to enter the armed complex from gate No 1 at around 11:30am. However, they tried to move to another check post when security guards intercepted them and security forces retaliated swiftly and effectively and killed four terrorists during an hour long action while six security personnel were martyred in the operation. The security officials informed that at second check post near Hilal Road square, the vehicle was stopped for identification by security officials. But, the terrorists left the vehicle and took their positions within a moment and opened firing on army personnel. They also threw some hand grenades on the check post due to which six army personnel including Brig Anwar-ul-Haq and Lt. Col. Waseem were martyred. Major General Athar Abbas Director General (DG) Inter Services Public Relations (ISPR) confirmed that terrorists wearing forces uniform and riding in a white Suzuki van attacked first check post with automatic weapons. On the resistance of security guards, they tried to move towards another check point while four terrorists were killed during exchange of fire, he added. Spokesman Pakistan armed forces further told that six army personnel embraced martyrdom during the gun battle with suspected militant outside army headquarters. Soon after the attack, security personnel cordoned off the whole area and search operation started in the area while air surveillance, with a view to locate the fleeing militants, was also commenced in the adjacent areas of GHQ. Initially, it was said that the terrorists had been overpowered and the situation was under complete control. But it proved untrue as military officials later said that two more militants were still at large, after reports of sporadic gunfire in and around the compound. Media sources said firing was still going on with up to five gunmen who had taken shelter in a security office and held hostage some 15 security men late night till filing of this report. After the attack on GHQ, soldiers sealed off roads leading to the headquarters and helicopter remained hovering over the area to locate the escaped terrorists. A high police official, on the condition of anonymity, told the reporters that the terrorists had latest guns, grenades and rocket launchers in such a big quantity , that they could fight for several hours but due to heroic retaliation from Pak Army, the terror campaign remained only for an hour or so. After the incident people began to gather in large numbers but they were stopped near GPO Chowk. The army and police commandos cordoned off the whole area and traffic was diverted from Mall Road to other routes of the city. The educational institutions were closed down and the parents rushed towards schools to collect their children. The security of all sensitive places in Rawalpindi was beefed up and extra contingents of police were deployed at different places. Agencies add: Government ministers blamed the Taliban, who have also vowed to avenge the death of their leader Baitullah Mehsud in a US drone missile attack in August. Another military official in Islamabad said there were at least six attackers in the assault on the heavily-fortified army command centre. Four were killed. Two are still missing. The hunt is going on, said the official with Armys media wing. He blamed the attack on Tehreek-e-Taliban Pakistan (TTP). An AFP journalist at the scene of Saturdays gun battle reported that the firefight began just before midday and lasted about an hour and a half, with helicopters ferrying the dead militants away after the battle ended. Witnesses said that the militants hurled hand-grenades, with one man saying five explosions rang out amid the gunfire. A car was signalled to stop outside Army headquarters, local police officer on the scene Amjad Ali told AFP. The occupants opened fire and threw grenades at security guards who retaliated. Prime Minister Yousuf Raza Gilani strongly condemned the attack, a brief statement issued by his office in Islamabad said, and met the Army Chief and the President to discuss the security situation. Police officials said that security had been beefed up in Islamabad, amid fears of more insurgent strikes. Monitoring Desk adds: Tahreek-e-Taliban (Amjad Farooqi Group) has claimed responsibility of the attack on Army headquarters. In a telephone call made to a private TV channel, a member of TTP Group demanded halt to operation in northern areas, accountability of former President Pervez Musharraf, return of Blackwater and closure of Western NGOs. APP adds: Security officials are trying to manage the safe release of hostages being held by the assailants at the GHQ, ISPR officials said on late Saturday night. More than two, probably four to five, terrorists are holding 10 to 15 hostages belonging to GHQ security staff, inside their office building, the officials told media. The terrorists entered the building while making a run towards Check Post No 2 after initially facing resistance at the Check Post No 1 where all the causalities occurred. In this regard, Director General Maj Gen Athar Abbas said four to five four to five terrorists were present in the building who made 10 to 15 persons as hostage, adding that the security forces had surrounded the area.