* Gunfire, explosions rock Jalalabad after suicide blasts
* Three bombers, seven security force members killed
* Rare attack on Pakistan by radical Islamist movement
* Highlights growing Islamic State threat in Afghanistan (Adds comment from government official)
By Rafiq Shirzad
JALALABAD, Afghanistan, Jan 13 (Reuters) - Islamic State claimed responsibility for a suicide attack on the Pakistani consulate in the eastern Afghan city of Jalalabad on Wednesday, stoking fears over the spread of the ultra-radical movement in Afghanistan.
Afghan officials said all three attackers and at least seven members of the security forces died during the attack by the Islamic States, which hitherto had not struck high-profile Pakistani targets in Afghanistan.
The attack, which coincided with efforts to restart the stalled peace process with Taliban insurgents and ease diplomatic tensions between India and Pakistan, added a dangerous new element to Afghanistan's volatile security mix.
"This is a major concern for us if they carry out more attacks like this," an Afghan security official said. "We have enough problems to deal with already."
Nangarhar, the province in which Jalalabad is located, has become the main Afghan stronghold of Islamic State (IS), which has battled the Taliban for leadership of the Islamist insurgency, attracting many former Taliban militants.
But IS has not so far been regarded as ready to organise and mount a complex attack involving suicide bombers and gunmen hitting a major urban target, said the security official, who spoke on condition of anonymity.
Attaullah Khogyani, a spokesman for the provincial governor, said a suicide bomber had tried to join a queue of people seeking visas to Pakistan and blew himself up after being prevented from entering the building.
Witnesses in Jalalabad, the main trade gateway to the Khyber Pass and Pakistan, said heavy gunfire and a series of explosions could be heard during a battle that lasted several hours, and residents and children from a nearby school were evacuated.
Islamic State said on its official Telegram messaging service channel that three members wearing suicide-bomb vests carried out the attack, which it said had killed dozens of people including "several Pakistani intelligence officers".
It said two suicide attackers had been killed while a third escaped.
Pakistan condemned the attack but said all members of the consulate staff were safe, with one official slightly injured by broken glass.
The attack carried echoes of one last week on the Indian consulate in the northern city of Mazar-i-Sharif, when a group of assailants barricaded themselves in a house and resisted security forces for about 24 hours after a suicide bombing.
Delegates from Afghanistan, Pakistan, China and the United States met this week to try to resurrect efforts to end nearly 15 years of bloodshed in Afghanistan, even as fighting with the Taliban intensifies.
In Pakistan on Wednesday, at least 14 people were killed in am explosion near a polio vaccination centre in the southwestern city of Quetta. (Additional reporting by Ahmad Sultan and Mirwais Harooni and Andrew MacAskill in Kabul, Tommy Wilkes in Islamabad and Omar Fahmy in Cairo; Editing by Robert Birsel and Miral Fahmy)
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