<P> Introduced in light of the ballistic missile threat from Pakistan, it is a double - tiered system consisting of two interceptor missiles, namely the Prithvi Air Defence (PAD) missile for high - altitude interception, and the Advanced Air Defence (AAD) Missile for lower altitude interception . The two - tiered shield should be able to intercept any incoming missile launched 5,000 kilometers away . </P> <P> PAD was tested in November 2006, followed by AAD in December 2007 . With the test of the PAD missile, India became the fourth country to have successfully developed an Anti-ballistic missile system, after United States, Russia and Israel . On 6 March 2009, India again successfully tested its missile defense shield, during which an incoming "enemy" missile was intercepted at an altitude of 75 km . </P> <P> On 6 May 2012, it was announced that Phase - I is complete and can be deployed to protect two Indian cities at a short notice . New Delhi, the national capital, and Mumbai, have been selected for the ballistic missile defence shield . After successful implementation in Delhi and Mumbai, the system will be used to cover other major cities in the country . This shield can destroy incoming ballistic missiles launched from as far as 2,500 km away . When the Phase II is completed and PDV is developed, the two anti-ballistic missiles can intercept targets up to 5,000 km both at exo and endo - atmospheric (inside the atmosphere) regions . The missiles will work in tandem to ensure a hit probability of 99.8 per cent . </P> <P> Apart from DRDO's endeavour to develop a potent missile defense, India is reportedly examining the Israeli Arrow, the Almaz design bureau's S - 300 PMU - 1 / - 2 and S - 400 and the Antey design bureau's Antey 2500 / S - 300VM . India has procured a squadron of S - 300V systems which are in use as an' anti-tactical ballistic missile screen' . </P>

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