The new Pakistani Taliban group behind the suicide bombing on the Wagah border said the attack was aimed at India as much as Pakistan, suggesting that Indian targets might be next.

At least 57 Pakistanis were killed during the popular flag-lowering ceremony on Sunday when a bomber tried to get as close as possible to the border in a possible attempt to cause casualties on the Indian side as well.

Ehsanullah Ehsan, a prominent militant and spokesman for the group, Tehreek-e-Taliban Pakistan Jamaat Ahrar (TTP-JA), claimed that he had warned Prime Minister Narendra Modi that attacks on India were in the pipeline.

"I have already conveyed it to Modi ... that if our suicide bombers can carry out attacks on this side of the border, they can easily do it on other side of the border in India," he told Reuters by telephone from an undisclosed location.

He earlier tweeted in English: "You (Modi) are the killer of hundreds of Muslims. We wl (will) take the revenge of innocent people of Kashmir and Gugrat" (sic).

According to Reuters, an Indian intelligence official said the account appeared genuine.

Gujarat - misspelt in the tweet – saw communal riots in 2002 that killed more than 1,000 people, most of them Muslims, when Modi was chief minister.

Pakistani militants have long targeted India, particularly during the 2008 Mumbai attacks in which 166 people were killed when Pakistani gunmen went on a three-day rampage in India's financial capital.

Ehsan said however that the Sunday attack was specifically aimed at the Pakistani military.

"We have proudly stated that our target was the Pakistani security forces and their installations in which we succeeded," Ehsan told Reuters.

The daily border parade, which draws hundreds of people, is conducted by the military of both sides, making it a symbolic target for Taliban militants fighting to topple the Pakistani government and establish an Islamic theocracy.

The central Pakistani Taliban group, known as the TTP, has effectively disintegrated this year and split into a range of smaller groups, such as TTP-JA who appear to be exploiting their ties to al Qaeda to broaden their mission beyond Pakistan.

Ehsan said that his outfit sought to attack countries around the region, unlike the TTP's narrow focus on war in the tribal areas on the Afghan border.

"The TTP focuses on Pakistan only, while we have a global agenda of jihad ‎and therefore we have people from all over the world including the Arab and Western world for this mission," he claimed.

TTP-JA has announced its support for the Islamic State in the Middle East, and its openly anti-Indian rhetoric differs from that of the mainstream Pakistani Taliban, who are mainly focused on their insurgency against Pakistani security forces.

A successful attack on an Indian target would severely affect the already frosty relations between India and Pakistan.

Meanwhile, al-Qaeda chief Ayman al-Zawahiri, said to be close to TTP-JA, earlier announced the creation of a South Asia wing of al Qaeda, threatening to stage attacks on countries across the subcontinent.

The new group's first major attack was a botched attempt in September to hijack a Pakistani warship and attack a U.S. navy vessel at a base near the port city of Karachi.

On Tuesday, India's navy reportedly withdrew two warships from Kolkata Port after intelligence agencies warned of an attack on the port by Pakistani militants posing as fishermen.

To Learn More:

Taliban group threatens to attack India following border blast (by Jibran Ahmad, Reuters)

Officials fear al Qaeda grooming Indian militants for big attacks (by Sanjeev Miglani, Reuters)

Kolkata port on high alert after terror threat (Hindustan Times)

Threat to Kolkata Port Forces Highest Alert (by Monideepa Banerjie, NDTV)