AHMADABAD, India -- The day after the deadly train fire that ignited Hindu-Muslim violence in western India, local authorities blamed the attack on a railroad platform fracas among angry Muslim tea vendors and slogan-chanting Hindus.

Nearly a week later, conspiracy theories abound about who was behind the assault, which claimed 58 Hindu lives and set off riots and attacks that left more than 500 people dead, most of them Muslims.

Indian officials, as they often do, hinted at a Pakistan link to the train fire in Godhra on Feb. 27. Other Indians wondered if Islamic militants had a hidden hand in lighting the fire.

Islamic Pakistan has denied involvement and called on India to stop the killings of Muslims, who are a minority in India.

What appears clear is that Hindus and Muslims in this western desert state don't blame their neighbors, even though they may have turned on them in anger or fled them in fear. They blame religious extremists and outside influences.

'Needle of suspicion'

"All this, blame the Hindu and Muslim fundamentalists," said Satish Aggarwal, a Hindu whose milk shop survived the riots. "We blame the Muslims in Godhra for starting it. But we know the ISI, Pakistan's intelligence service, was behind that."

Aggarwal, surveying the damage in his community in Ahmadabad, the commercial capital of Gujarat state, was expressing a common belief held by Indians: Pakistan and its Inter-Services Intelligence spy agency, ISI, is behind many of their woes.

"The needle of suspicion" pointed to some "outside terrorist outfit," said India's Home Minister L.K. Advani.

Vipul Vijoy Singh, head of Gujarat's anti-terrorism squad, said Indian intelligence officials were investigating whether ISI agents had a hand in provoking the train fire.

"Intelligence is working very hard on various reports on anti-national elements operating within the country and those who are funding operations from outside," Singh was quoted as saying in Tuesday's The Asian Age newspaper.

Police have arrested 27 people in the train massacre, including Mohammed Hussain Abdul Rahim Kalota, a Muslim who is chairman of the Godhra municipality.

Indian government spokeswoman Nirupama Rao said Pakistani involvement could not be ruled out, adding "there is every reason for us to investigate whether there is a larger design to this whole situation."

Indian and Pakistani soldiers have been nose-to-nose along their disputed frontier for months, since India blamed the ISI and Pakistan-based Islamic militant groups for the Dec. 13 attack on its Parliament that left 14 people dead.

A main point of contention is disputed Kashmir, over which the neighbors have fought two wars. New Delhi accuses Pakistan of supporting Islamic separatists in India-held Kashmir. Islamabad says it gives the militants only moral support.

Pakistan scoffed at accusations it was involved in the train attack.

"People within and outside India expect an early end to the ongoing genocide rather than indulging in the game of blaming others," said a statement from Pakistan's government.

The blame game resumed Tuesday, in ways that Pakistan likely would applaud.

Police in Ahmadabad filed several reports accusing local leaders of Prime Minister Atal Bihari Vajpayee's Hindu nationalist party and the fundamentalist World Hindu Council of leading Hindus into Muslim communities and commanding them to burn Muslims alive.

Gujarat state secretary for the World Hindu Council, Jaideep Patel, denied that members of his group were involved in the attacks.

Pran Chopra, a political scientist with India's Center for Policy Research, said Hindu-Muslim riots have traditionally been orchestrated by those with power. In this case, that would be Muslim political leaders in Godhra and Hindu nationalists in Gujarat.

"The conspiracy theories are neither completely true, nor are they entirely baseless," Chopra said.

When asked if Pakistan or possibly Osama bin Laden's al-Qaida terrorism network could have had a role in the train fire, Chopra said he would not rule out indirect involvement.

"The parentage of the al-Qaida and the parentage of those who might have planned this might be the same," he said. "The very people who produced the al-Qaida are the people who have their own sympathizers and supporters in Gujarat."

Kanti Bajpai, a professor of international affairs at Jawaharlal Nehru University in New Delhi, said the train attack appeared to be a well-planned assault and may have been Muslim extremists trying to polarize the communities.

"It was tailor-made to make riots in a very calculated way," Bajpai said.

Still, he believes the root of the riots lie in the north Indian town of Ayodhya, which Hindus believe is the birthplace of their most revered god, Rama.

Most of the Hindus killed on the train were activists returning from a pilgrimage to Ayodhya. The World Hindu Council insists it will begin prayer ceremonies in Ayodhya next week in preparation for building a Rama temple, defying court orders to wait.

Muslims deeply resent the temple project as the site is where a 16th-century mosque was torn down by Hindus in 1992, provoking riots that killed 2,000 people.

"We know historically that when the temple issue is roiled up, there's going to be communal violence," Bajpai said.

Relations between Hindus and Muslims have been rocky since the end of British colonial rule in 1947. An estimated 1 million Hindus, Muslims and Sikhs were killed in rioting that accompanied the partition of Pakistan from the Indian subcontinent. Still, they have lived in relative harmony in India and clashes are rare.