Saudi officials sought Sunday to reassure foreign oil executives -- and prevent a dramatic rise in crude prices (search) -- after the lethal attack on two compounds housing offices and homes of expatriates working in the country's most important industry.

The weekend rampage by gunmen that killed at least 10 people in the Saudi city of Khobar (search) was the second such attack in less than a month. Saudi officials and foreign analysts voiced concern that it might frighten some would-be investors and oil service company employees from doing business in Saudi Arabia (search).

At the same time, they worried that the attack -- which killed an American oil man, a British oil company executive and an Italian cook -- might inflame fears about political stability there and drive oil prices higher when trading resumes on futures markets later in the week.

U.S. crude prices eased last week to less than $40 per barrel after Saudi Arabia assured major importing nations that it would boost its production and urge its OPEC (search) partners to do likewise.

Futures exchanges in New York and London would be closed for holidays on Monday, delaying the market response.

"There's bound to be a bump in prices," said Yasser Elguindi of New York-based Medley Global Advisors. However, the three-day weekends in the United States and Britain should give markets more time to digest the events in Saudi Arabia and help temper any panicked response, he said by telephone from Cairo.

In spite of the ferocity of the attacks in Khobar, oil companies are used to dealing in environments that are even more hostile and threatening, such as parts of Africa and Central Asia. Analysts said the attack and seizure of hostages in Khobar was unlikely to trigger a mass departure of expatriates from the kingdom.

One 20-year American resident of Dhahran, a neighboring city, agreed.

"If I really felt that the general Saudi population didn't want us there -- that we as Americans were not welcome -- then that would be the time I would think about leaving. But that's not the case," said Kathleen Owen, a consultant for the state-run Saudi Arabian Oil Co., known as Saudi Aramco.

She spoke in a telephone interview from Pennsylvania, where she and her family were vacationing before their planned return to Dhahran later in June.

The U.S. Embassy in Saudi Arabia reiterated a call to its citizens to leave the kingdom. British Ambassador Sherard Cowper-Coles said the British government has adjusted its own travel advisory to reflect what happened, but said: "We are not advising them to leave the kingdom."

Even if expatriate oil executives, engineers and technicians did leave, some analysts argued that the long-established Saudi practice of replacing foreign experts with qualified local staff should protect its status as the world's top crude exporter. Saudi Aramco began an intense effort to "Saudi-ize" its work force more than five years ago.

"Senior expats have given way to well-trained locals. Many of these guys are really pretty good," said Peter Gignoux, a London-based oil adviser for GDP Associates of New York.

The number of foreigners working in the Saudi oil industry is unclear, but reliable estimates range from 5,000 to 30,000. They include drivers and nurses as well as top managers. Many live in guarded, suburban-style compounds like the ones targeted by the gunmen in Khobar, 250 miles northeast of the capital, Riyadh.

Saudi Oil Minister Ali Naimi met western oil executives Sunday to reassure them about the safety of their staff and investments in the kingdom, according to an oil industry source in Saudi Arabia, speaking on condition of anonymity.

"We feel it is our responsibility to make them feel like they're staying in a comfortable place and that they feel safe at all times," the source said.

A Saudi official familiar with security affairs, speaking on condition that he not be identified, said the government has decided to expand its protection of sensitive facilities to include offices with significant expatriate staff. He said a battalion of the elite Saudi National Guard, which reports directly to Crown Prince Abdullah, would be deployed from its base in the country's eastern province to fulfill that task.

One of the targeted oil industry compounds contains offices and apartments for the Arab Petroleum Investment Corporation, or Apicorp, and the other -- the Petroleum Center building -- houses various international firms.

Three Apicorp employees and the son of an employee were among the dead, the company said in a brief statement published in the Saudi newspaper Al-Jazirah. Apicorp is the investment arm of the Organization of Arab Petroleum Countries.

Offices at the Petroleum Center include a joint venture among Royal Dutch/Shell Group, Total SA and Saudi Aramco; Lukoil Holdings of Russia; and China Petroleum & Chemical Corp., or Sinopec. These four foreign firms signed deals recently to explore for natural gas in Saudi Arabia.

All of those employees were safe, said Shell spokesman Simon Buerk and a Saudi oil industry official, Yahya Shinawi, though it wasn't clear whether other companies had accounted for all their employees.

Nail al-Jubeir, a spokesman for the Saudi Embassy in Washington, told CNN that the gunmen's targeting employee compounds was a sign of desperation.

"I think they know they will not be able to get the installations themselves so they target the people who work there. ... It does not take much to come into a building with a rifle and shoot innocent people. Unfortunately it is very difficult to guard against," he said.

Saudi Arabia pumped 8.5 million barrels of oil per day in May and has pledged to produce 9.1 million barrels in June -- more than 10 percent of global crude supplies. Leo Drollas of the Center for Global Energy Studies in London said the assault in Khobar would have little immediate effect on the Saudi oil business.

No pipelines, ports or other export facilities were targeted, just as in the May 1 attack on offices of Houston, Texas-based ABB Lummus Global Inc. in the western city of Yanbu. Six Westerners and a Saudi died in the Yanbu attack.

"It's not cataclysmic, just another serious episode to worry about. No oil facilities were hit, and at the end of the day, that's what counts," Drollas said.

Because investments in oil and gas projects can take years to negotiate, the Khobar attack probably won't affect projects already underway. However, several analysts predicted that the latest violence would squeeze funding in the future.

"If you're sitting in a board room in Geneva or London or what have you, you're going to think twice about pumping more money in," said one analyst, speaking on condition of anonymity.

At the very least, foreigners will probably demand higher salaries or hazard pay for working in Saudi Arabia.

"The question really is at what cost people will be doing business there," said Elguindi of Medley Global Advisors.