Both Pakistan and India say they have carried out test-launches of short-range, nuclear-capable missiles on Wednesday.
The Indian defence ministry first said it had concluded a successful launch of its Prithvi surface-to-surface missile from the Chandipur test site in eastern Orissa state.
Shortly afterwards the Pakistani foreign ministry said it had test-fired an Abdali missile.
Pakistan said it had informed India about its launch but that it was taken by surprise by the Indian test-firing.
Indian defence ministry spokesman Baljit Singh Menon said the Prithvi launch was a routine test to improve the version to be used by the army.
"The launch was witnessed by senior army officials. All the objectives of the mission were met," he said.
Pakistani foreign ministry spokesman Aziz Ahmed Khan said shortly afterwards: "Pakistan has also test-fired a missile today, but we informed India about it."
Pakistan said it was not warned of the Prithvi missile test
Mr Khan said of the Indian launch: "They didn't tell us about it beforehand."
It was not immediately clear which country was the first to conduct a test on Wednesday.
Pakistan and India have carried out tit-for-tat missile tests several times in recent months and have also expelled several of each other's diplomats.
The nuclear rivals have fought three wars since 1947 and came to the brink of
conflict again last year.
India's Prithvi missile has a range of 150 kilometres (90 miles) and can carry a one tonne payload.
It is part of an arsenal that includes the Trishul surface-to-air missile and the intermediate-range Agni, which could hit most of Pakistan.
Pakistan's Abdali surface-to-surface missile has a range of up to 200 km (125 miles).
India's launch on Wednesday took Indian military analysts by surprise as
such an exercise was not expected during the Iraq war.
"It has nothing to do with the war but the timing is a bit unusual," a senior military official told the AFP news agency.