Pakistan and neighboring India exchanged lists of their nuclear facilities on Sunday as part of a 1988 pact that bars them from attacking each other’s nuclear installations, according to the official statements from both sides.

The countries have had strained relations since their independence from colonial British rule in 1947 over the Himalayan region of Kashmir. They have fought three wars since and have had a number of military skirmishes in recent years.

Meanwhile, both countries built up their armies and developed nuclear weapons. India conducted its first nuclear test in 1974, while Pakistan carried out its first test in 1988.

Last year an Indian missile accidentally landed in Pakistan, setting off alarm bells across the world.

The lists regarding data about nuclear facilities and assets are exchanged annually on Jan. 1 and it's said India had simultaneously handed over a list to the Pakistani mission in New Delhi. This practice has been in place since 1992.

"The list of nuclear installations and facilities in Pakistan was officially handed over to a representative of the Indian High Commission in Islamabad at the Ministry of Foreign Affairs today," Pakistan's Foreign Ministry said in a statement.

With the help of China, Pakistan has recently increased its use of nuclear energy to meet the rising demand for electricity.

In a separate statement, Pakistan's foreign office said the two countries had also exchanged a current list of each other's citizens held in prisons.

India and Pakistan share the lists of prisoners in each other’s custody as part of another agreement between the countries, dating back to 2008.

Pakistan shared a list of 705 detained Indians, 51 civilians and 654 fishermen. India shared a list of 434 Pakistanis in its custody, 339 civilians and 95 fishermen.

India and Pakistan arrest each other’s fishermen for crossing the unmarked sea frontier between them. Their maritime security agencies seize the boats and jail the fishermen, who are usually only released after the two countries hold negotiations. Normally they spend years behind bars with no formal trial.

The 2008 agreement gives each side consular access to prisoners and requires them to exchange lists of prisoners in each other’s custody each January and July.

Pakistan separately also sought consular access to its missing defense personnel from wars in 1965 and 1971 and special consular access to another 56 civilian prisoners.