By Maria Golovnina
ISLAMABAD (Reuters) - A Pakistani Taliban group behind this week's devastating suicide bombing on the Pakistani-Indian border has said the attack was as much aimed at India as Pakistan, suggesting that Indian targets might be next.
At least 57 Pakistanis were killed during a 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.
In a tweet issued after the attack, the splinter group, Tehreek-e-Taliban Pakistan Jamaat Ahrar (TTP-JA), said it was determined to attack both sides.
"This attack is an open message to both governments across the border," TTP-JA spokesman Ehsanullah Ehsan said in an Urdu-language message. "If we can attack this side, the other side could also be attacked."
He also tweeted in English: "You (Indian Prime Minister Narendra Modi) are the killer of hundreds of Muslims. We wl take the revenge of innocent people of Kashmir and Gugrat" (sic).
Kashmir is a disputed Himalayan territory over which India and Pakistan have fought two of their three wars. Gujarat - misspelt in the tweet - is a western Indian state where more than 1,000 people, most of them Muslims, were killed in inter-religious rioting in 2002, when Modi was its chief minister.
The authenticity of the tweets could not be immediately verified and then did not show on Ehsan's Twitter page as of Wednesday morning.
India has long accused Pakistani militants of trying to attack its targets, particularly after the 2008 Mumbai attacks in which 166 people were killed when Pakistani gunmen went on a three-day rampage in India's financial capital.
TTP-JA is a new outfit that broke away from the mainstream Taliban movement in September and has announced its support for the Middle Eastern group Islamic State, whose belligerent anti-Western ideology has begun to inspire militants across South Asia.
TTP-JA's openly anti-Indian rhetoric differs from that of the mainstream Pakistani Taliban, who are mainly focused on their insurgency against Pakistani security forces in the volatile tribal northwest of the country.
A successful attack on an Indian target would severely affect the already frosty relations between the nuclear-armed rivals.
Shelling on their disputed Kashmir border is an almost daily occurrence, a constant reminder that a full-blown conflict is always a threat.
Further unnerving India, al-Qaeda chief Ayman al-Zawahiri, said to be close to TTP-JA, has 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 withdrew two warships from the eastern port of Kolkata after intelligence agencies warned of an attack on the port and the city.
(Additional reporting by Sanjeev Miglani in New Delhi, Writing by Maria Golovnina; Editing by John Chalmers and Jeremy Laurence)