ISLAMABAD: A senior foreign ministry official said on Thursday Pakistan is "seriously concerned" by India's current test of anti-ballistic missiles which media reports say could interrupt incoming nuclear armaments, warning Pakistan would improve its defences.

India's defence and foreign ministries did not respond to requests for comment and the defence ministry has not stated whether any test was conducted. India has not announced these tests in the past. 

The string over the missile test is likely to intensify long-running stress between India and Pakistan, nuclear-armed neighbours who have fought three wars since being divide amid aggression at the end of British majestic rule in 1947. Both the country has been on the rise missiles of anecdotal ranges since they conducted nuclear tests in May 1998.

According to media reports, on May 15 India tested a locally designed Anti-Ballistic Missile system which could in theory intercept a nuclear-carrying ballistic missile.

Islamabad views its nuclear arsenal as a deterrent against India's much larger conventional military.

Sartaj Aziz, foreign affairs adviser to Pakistan's prime minister, told the senate that India's latest test, as well as recent tests of nuclear capable submarine-based ballistic missiles, was "leading to nuclearization" of the Indian Ocean.

"Pakistan has serious concerns over these developments and will take all necessary measures to augment its defence capabilities," Aziz said.

Pakistan alleges India is building large nuclear-powered submarines capable of carrying nuclear-armed missiles.

Aziz said that India's actions were upsetting the strategic balance in South Asia and affecting the maritime security of other Indian Ocean nations.

"We are not oblivious to our defence needs and will have to upgrade our defensive capabilities through suitable technologies without entering into an arms race," Aziz said, according to a foreign ministry statement.