Britons told: Don't travel to India

British and American nationals were told to consider leaving India yesterday amid growing alarm over the potential for nuclear war with Pakistan over the disputed territory of Kashmir.

Both the Foreign Office and the US State Department advised people to cancel plans to visit the country. Non-essential diplomatic staff and officials' families have also been told they can leave.

Under intense international pressure, India and Pakistan appeared to be edging back from the brink of war. George Fernandes, the Indian Defence Minister, said the situation along Kashmir's Line of Control – where both sides have amassed some one million troops – was "stable".

But tensions remained high, with the two sides exchanging fire across the Line of Control for the 16th day running, and the Foreign Office stepped up its warning to travellers not to visit neighbouring Pakistan and urged British nationals already there to consider leaving because of the heightened tensions.

The new advice affects an estimated 20,000 Britons and 60,000 Americans living in India, including an estimated 1,000 British tourists who are expected to be flown home. Britain has 150 diplomatic staff in India, with some 200 dependants.

The Foreign Secretary, Jack Straw, issued the "precautionary" advice, warning of "heightened tension and increased risk of conflict" between India and Pakistan, after visiting Delhi earlier this week as part of a diplomatic mission to ease increasing tension in the region.

Mr Straw discussed Kashmir with Colin Powell, the US Secretary of State, by telephone yesterday. Mr Powell said: "There are tens of thousands of American citizens in both countries and they will make their own decisions. We are also reinforcing our travel advisory warning people that this is probably not the best place to visit and travel to."

The advice indicates the seriousness with which officials regard the stand-off. Mr Straw said the travel warning was being issued "for the time being" until the situation in Kashmir improves. He said: "The situation is dangerous. War is not inevitable but it is important that we should exercise our duty of care as carefully as we can." Britain halved its diplomatic presence in Pakistan last week following threats from Islamic extremists.

Donald Rumsfeld, the US Defence Secretary, is due to visit the sub-continent within days – a move broadly welcomed by General Pervez Musharraf's government – as part of a concentrated diplomatic push to draw the two nations back from the brink of war.

Reports suggested that Pakistani troops had moved from the Afghan border and may be redeployed in Kashmir. Pakistan is believed to have some 6,000 troops engaged in the search for al-Qa'ida forces.

American spokesmen warned that one instance of "irresponsible" behaviour could precipitate disaster. But speaking at an anti-terrorism conference in Singapore, Mr Rumsfeld's deputy, Paul Wolfowitz, said a conflict would be "somewhere between terrible and catastrophic".

Mr Powell said both nations understood the consequences of a nuclear exchange. He said: "The whole world would condemn whoever does that. That is a sobering reality that both understand." He added: "What I am impressed with right now is that both sides seem to be looking for a political solution. Both sides realise that little can be gained from a war."

Atal Bihari Vajpayee, the Indian Prime Minister, is refusing to hold a face-to-face meeting with General Musharraf at an Asian security summit in Kazakhstan next week. He has ruled out the idea until "cross-border terrorism" by Islamic militants against its portion of Kashmir have halted.