Tensions between India and Pakistan pose a threat to the whole world, Tony Blair has warned as he urged both countries not to plunge the region into war.

His appeal came as the UK called back more than 150 diplomats from Pakistan and Britons were urged to leave the country amid threats to their safety from terrorist groups.

There is a pressing need for an end to terrorism, a lowering of tension and then dialogue

Jack Straw Foreign Secretary

The UK prime minister told MPs the dangers thrown up by the stand-off between the two military powers in disputed Kashmir could not be stressed enough.

"I do urge both countries... to pause and reflect before taking action that could plunge not just their countries into conflict but the wider region - with implications for the whole of the world," he said.

'End terrorism support'

He called for Pakistan to end any support for terrorism in Kashmir or elsewhere in the region while India should offer dialogue to resolve such disputes.

Foreign Secretary Jack Straw is due to visit both India and Pakistan next week to try to calm tensions over Kashmir.

Indian Prime Minister Vajpayee tells troops in Kashmir to prepare for a "decisive battle"

The UK's decision to withdraw diplomats from Pakistan was the result of security threats and not connected to the Kashmir crisis, said Mr Straw.

"We will begin reducing the number of staff and dependents in Pakistan with immediate effect," he said.

"We are now advising against all but essential travel to Pakistan and then only where there is a compelling reason and where security is assured.

"We are also advising British nationals in Pakistan to consider leaving."

Offices closing

The numbers of diplomats, staff and their families with the British High Commission in the capital Islamabad will be cut from about 210 to about 80.

The Deputy High Commission in Karachi will see a cut from 36 to 10, while the office in Lahore, which currently has about 10 Britons attached to it, will close.

Mr Straw did not say where the threats came from, but pointed to a recent series of "terrorist outrages".

The three visa offices in Pakistan's main cities have been closed, and the British Council has shut its doors to the public.

'No pre-cooked plan'

Any remaining British citizens are being warned to take particular care over their own personal security.

Mr Straw's warning came after he announced he would visit India and Pakistan to try to calm the mounting tensions in the region.

The UK minister says he has no "pre-cooked" peace plan but hopes he can help persuade both sides to strike up a peaceful dialogue.

Jack Straw: Potentially devastating conflict warning

On Tuesday, he said: "The possibility of war between India and Pakistan is real and very disturbing.

"This is a crisis the world cannot ignore."

Both countries have nuclear arsenals and Mr Straw stressed that they had talked publicly about a possible nuclear exchange.

British targets

"It is therefore a conflict with potentially devastating consequences for the people of both countries and of profound concern to the whole of the international community.

"There is a pressing need for an end to terrorism, a lowering of tension and then dialogue."

There have been fears the British community in Pakistan could become a target for Islamic extremists.

Those concerns have grown since British forces joined the American-led operation inside Afghanistan against al-Qaeda and Taleban.

Car bomb

There have been three attacks on foreigners since the beginning of the year.

The American journalist, Daniel Pearl, was kidnapped and subsequently murdered.

Then an Islamabad church used by the international community was attacked, killing among others an American diplomat's wife and daughter.

Two weeks ago, a car bomb exploded next to a navy bus in Karachi, killing 14 people, 11 of them French technicians.