| KANDAHAR, Afghanistan
KANDAHAR, Afghanistan The United Nations said on Tuesday it had shut its mission in Kandahar and evacuated many foreign staff from the southern Afghan city, in a sign of worsening security before a major U.S. offensive.
Hours after the announcement, suspected Taliban infiltrators blew up tankers at a fuel depot outside the city, near the airfield that serves as the biggest NATO base in the province, killing four people and wounding at least 30.
A spokesman for Kandahar province Zalmai Ayoubi said there were several blasts and that one of them could have been caused by a suicide bomber.
Sher Mohammad Zazai, a senior Afghan army commander in the south, said 10 guards at the depot were among those wounded in the attack. NATO spokesman Major Marcin Walczak said the blast was a few thousand meters (yards) from the base. No NATO troops were hurt.
The U.N. pullout alarmed residents already anxious over a U.S. plan to launch the biggest operation of the nearly nine-year-old war in coming weeks with thousands of U.S. and Afghan troops.
U.N. spokeswoman Susan Manuel said all Afghan staff in Kandahar had been told to stay home, and some foreign staff had been moved to the capital Kabul for their safety a day earlier.
She would not say how many international staff had stayed behind, or whether a specific threat was behind the decision.
"The security situation has gotten to the point where we needed to withdraw them yesterday," she said. "We hope people can go back and keep doing what they have been doing. We see it as a very temporary measure."
NATO forces are planning what Washington calls a decisive campaign in coming months in Kandahar, the biggest city in the south and birthplace of the Taliban movement.
"When the U.N. is moving out of Kandahar, it shows that there is no security here," said shopkeeper Mohammad Achakzai. "We are very worried, we don't know what is coming upon us."
The offensive is the cornerstone of a "surge" strategy by U.S. President Barack Obama, employing the bulk of the 30,000 extra troops he is dispatching to Afghanistan this year to turn the tide against a mounting Taliban insurgency.
Under the plans, expected to begin unfolding in June, about 8,000 U.S. and Canadian troops will try to secure rural areas around the city while a brigade of 3,500 U.S. troops escorts 6,700 Afghan police into urban areas. In all, the offensive will involve 23,000 NATO ground troops, Afghan soldiers and police.
SURGE IN VIOLENCE
The last few weeks have seen a surge in attacks and assassinations in Kandahar, a city of about 500,000 people. Bomb strikes have occurred almost daily, insurgents have carried out several major suicide bombings and raids, and a deputy mayor was gunned down last week.
Kandahar's provincial council chief, President Hamid Karzai's half-brother Ahmad Wali Karzai, said the United Nations was over-reacting by withdrawing its staff.
"We strongly condemn this act by the U.N. to pull out of Kandahar. This is an irrational decision without consulting with local authorities," he told a news conference.
"The situation is not as bad as the U.N. views it," he said. "This move will leave a bad impression on citizens of Kandahar."
Taliban spokesman Qari Yousuf Ahmadi denied the group had threatened the United Nations: "They haven't done anything good for the people, so their presence or withdrawal does not make any difference. But we haven't warned or threatened them," he said by phone from an undisclosed location.
"The U.N. knows the coming operation is not going to be healthy for them, so they are making excuses to leave Kandahar."
(Additional reporting by Peter Graff in Kabul; Writing by Peter Graff; Editing by Mark Trevelyan)