LAHORE The Friday nights cyber attack on the website of Central Bureau of Investigation (CBI) - the top civilian investigation agency of India - in response to the attack on 40 Pakistani websites has intensified the cyber war between India and Pakistan which had started in 1998. According to the IT experts, there are hundreds of highly professional hackers operating in both the countries. However, the 'Predators PK and Indian Cyber Army claimed the recent attacks on the websites of India and Pakistan respectively. According to some computer security websites, since the start of cyber war, the Indian websites were being attacked mostly by two prominent Pakistani hacker groups, Pakistan Hackers Club (PHC) and G-Force. The founder of PHC is claimed to be Karachi-based while G-Force, consisting eight members, is from Lahore. On the Indian side, there are various hackers groups among whom the H2O or the Hindustan Hackers Organisation is the famous ones. As usual, the Indian media blamed that the Pakistani hackers, working for the Kashmir cause, were backed by the intelligence agencies. However, they admitted that at cyber-front, Pakistan had always been winning the war. The computer security websites say the attacks on Indian websites increased from four in 1999 to 72 in 2000 whereas the Pakistani websites were hacked seven times in 1999 and 18 in 2000. During the first half of 2001, 150 Indian websites were defaced. From 2002 to 2009, the cyber attacks were also witnessed on the key websites of the both countries. In the latest response to the ICAs attack on 40 Pakistani websites, Pakistani hackers claimed to have defaced some 270 Indian websites in a single go, including that of the CBI, which, according the IT professionals, triggered the internet war between the two countries hackers. Pakistani hackers describing themselves as 'Predators PK on various websites left an interesting message on a famous internet blog that reads: This attempt is in response to the Pakistani websites hacked by 'Indian Cyber Army. We told you before that we are sleeping but not dead. The message further warned: Remember PCA (Pakistan Cyber Army) is alive, go back kids or we will smoke your doors as we did before. It added, Let see what was your investigating agency so called CBI can do for you or for us Haha. On the other hand, among the dozens of websites hacked by the ICA, were the websites of the security agencies and the ministries of Education and Finance as well as Islamic organisations, as the hackers posted Indian slogans on the home pages of these websites. AFP adds: CBI authorities said they were working to restore the site, which offered information to the public. The spokeswoman said she could not comment on Indian media reports that more than 200 other Indian sites had also been attacked by Pakistani hackers. We came to know the CBI site had been compromised Friday night, the spokeswoman told AFP, asking not to be named. It will take us a couple of days to restore the site. The CBI has registered a case and is investigating the attack, she said. Monitoring Desk adds: Indian hackers group, called the 'Indian Cyber Army, hacked the Oil and Gas Regulatory Authority (OGRA) [] website on Saturday. The website was later recovered by the site administration. The message left on the Ogra page said the hack is in response to the attack on over 200 Indian websites by the 'Pakistan Cyber Army. The message reads: You Have Been Hacked By The INDIAN CYBER ARMY This Is a Retaliation Of Hacking 'CBI.