BEIJING (AFP) - The situation on the ground in North Korea appears normal and calm, tourists and guides said on Saturday, despite high international tensions and Pyongyang warning diplomats to consider leaving.

With the Korean peninsula in crisis and Pyongyang threatening a nuclear strike against the US, North Korean authorities have told embassies they would be unable to guarantee their safety if a conflict breaks out.

But tourists are still visiting the largely isolated state, with several groups on board a flight back to Beijing on Saturday.

"We're glad to be back but we didn't feel frightened when we were there," said Tina Krabbe, from Denmark, who spent five days in the country. "It didn't feel like there was much tension in the city. We were OK actually."

A 15-year-old from Hong Kong on a school trip said: "My mum thought a war was going to break out or something like that."

But he added: "What we saw was all peaceful. There was absolutely no conflict... there was no unrest."

Visitors said they had been able to watch BBC news in their foreigner-only hotels.

A man and woman with American accents, carrying hand luggage only and no souvenirs, declined to be interviewed and said they were not allowed to talk to the media.

Mr Nicholas Bonner, founder of Koryo Tours, who has been organising trips to North Korea for 20 years and visited last week, said life was "carrying on as normal".

"It is certainly tense, but people are going on with their daily work and tourism is continuing and people have been very hospitable," he told AFP.

"Everyone just hopes that it'll blow over." Tourist trips were still being allowed, he said, adding: "We would not take take tours if this would be in any way a risk to anyone.

"There was once in 20 years that we were not able to bring tourists in, it would have been 1994 or something like that. It only lasted a few days and then we were allowed back in again."

Western tourism to North Korea remains small-scale, with the country's marginalised nature acting as a draw for some travellers, but is only possible as part of an organised tour with local escorts.

Koryo Tours guide Amanda Carr, who goes to the country at least once a month and returned on Saturday from a two-day trip, said there was "not much difference" at the moment.

"It was a holiday yesterday so people were doing what they generally do on holidays, spending time with their families, everyone going about their daily life like usually on the streets," she said.

Tourists were unable to use 3G mobile phones to access the Internet, she added. The service was suspended soon after first becoming available some months ago.

Their local guides, she said, told them they "were not really afraid, not worried or anything and they believed their country was strong, and their leadership is strong enough to guide them in the right direction".