WASHINGTON, Nov 29: US President George W. Bush on Saturday called the terrorist violence in Mumbai an attack on “human dignity”, while US officials worried that the terror rampage could lead to a possible surge in violence between India and Pakistan.

US Secretary of State Condoleezza Rice has called the foreign minister of India twice, along with President Asif Ali Zardari, since the crisis began.

Ms Rice is also keeping President-elect Barack Obama in the loop. She has made three telephone calls to Mr Obama since the attacks began to update him on information coming from South Asia.

“There were very worrying tensions in the region,” said Gordon Duguid, a State Department spokesman. “She was calling the president of Pakistan to get his read on how those tensions might be affected.”

As US officials worked to ease tensions between India and Pakistan, they acknowledged that they were seriously concerned about a “significant deterioration” in the process of India-Pakistan reconciliation.

US officials who spoke to the media noted that India and Pakistan had already fought three wars and even if international efforts prevented another, the current situation had very “dangerous implications”. They predicted a flare-up in animosity similar to one that occurred after militants attacked the Indian parliament in December 2001.

President Bush also held an hour-long video-teleconference on Saturday with US diplomats in India to assess the situation.

In his nationally televised address, Mr Bush vowed not to allow the terrorists to have the final word.

“The killers who struck this week are brutal and violent. But terror will not have the final word,” he said. “We pledge the full support of the United States as India investigates these attacks, brings the guilty to justice and sustains its democratic way of life. As the people of the world’s largest democracy recover from these attacks, they can count on the people of world’s oldest democracy to stand by their side,” said Mr Bush.

“The people of India are strong. They have built a vibrant, multiethnic democracy. They can withstand this trial. The leaders of India can know that nations around the world support them in the face of this assault on human dignity,” he added.

Also on Saturday, US officials confirmed that six Americans were among the 195 people killed in the three-day violence that shook Mumbai.

Diplomatic observers here warned that the death of American citizens would force the US administration to increase pressure on Pakistan to rein in terrorist groups based inside its borders.

“I am really worried about its consequences for Pakistan,” said Christine Fair, a South Asia expert at a US think-tank, Rand Corporation. “It will have serious consequences for Pakistan’s relations with the United States as well.”Also on Saturday, the US media began to support Indian claims that the terrorists were linked to Lashkar-i-Tayyaba and were trained in Karachi. Several major US newspapers and television channels highlighted India’s claims, backing them up with similar claims by unidentified US officials and prominent American experts on South Asian affairs.

But US officials, when contacted for comments, said they were still not certain if Pakistan-based groups were involved, and that they believed that even if such groups were involved, they did not enjoy the support of the Pakistani government.

Washington has already sent an FBI team to India while a second group was on alert to join the first team if necessary. The State Department has warned US citizens still in Mumbai that their lives remain at risk.

The Pakistan Embassy in Washington also issued a statement, denying claims that Pakistan was involved in the attacks.

“Pakistan is confronting the menace of terrorism with great vigour,” said Ambassador Husain Haqqani. “It is unfair to blame Pakistan or Pakistanis for these acts of terrorism even before an investigation is undertaken.”

The situation forced both the incumbent and incoming US administrations to take a strong stance against the attacks. While the outgoing president made a special appearance on the lawns of the White House to condemn the attack, his successor Barack Obama spoke with Indian Prime Minister Manmohan Singh to reiterate Washington’s offer of both moral and material support to India.“These terrorists who targeted innocent civilians will not defeat India’s great democracy, nor shake the will of a global coalition to defeat them,” Mr Obama said in a statement issued after his call.

“The United States must stand with India and all nations and people who are committed to destroying terrorist networks, and defeating their hate-filled ideology.”

President Bush telephoned Prime Minister Singh on Thursday to offer similar support.