AMMAN, JORDAN, FEB. 4 -- Deteriorating economic conditions, a shortage of gasoline and growing anger over concentrated allied bombing of Iraq -- which has resulted in Jordanian casualties -- are contributing to hostility toward Americans here that is believed to have prompted the State Department's warning for all Americans to leave.

Concerns about a Jordanian backlash have increased following a small spate of explosions in Amman that diplomats and local observers believe were bombs aimed at U.S. citizens.

"When you have people cornered, they are going to do something unusual," said Abdel Salam Majali, president of the Amman-based World Affairs Council. Warning of possible repercussions, particularly in view of the war-related economic problems Jordan is experiencing, he added, "If they squeeze us, we have to bear up to a point, and then we have to burst."

A Western ambassador said of the anti-American mood here, "The demonstrations we have had so far have been inconsequential, but now we are dealing with a new situation."

The U.S. Embassy warned Americans here today that "the outbreak of hostilities in the Persian Gulf region has increased tensions in the area and resulted in a heightened risk to Americans." It said embassy operations in Amman are being sharply curtailed and normal consular operations suspended. Embassy services would be provided to U.S. citizens only in emergencies, the advisory said.

An embassy spokesman declined to say if there had been any specific threats to the mission.

In the 19 days since concentrated bombing began in the allied effort to drive Iraqi forces from Kuwait, Jordanians have been glued to their radios and televisions to keep up with the latest news. Many have relatives or close friends in Iraq and Kuwait, while others are asking why the United States is devoting so much energy toward driving Iraq from Kuwait when Washington has neglected for decades the issue of Israel's occupation of Arab lands.

Jordanians have tended to support Iraqi President Saddam Hussein throughout the gulf crisis, and popular frustrations with the gradual destruction of Jordan's principal ally are overpowering the reserve and politeness usually accorded to Westerners here.

The mood of hostility has grown so intense as to prompt King Hussein to publicly urge Jordanians to respect and honor guests in their midst. Nevertheless, recent incidents have given Americans and other Westerners cause for concern.

Western diplomats note for example a recent car-bomb explosion in a neighborhood west of Amman, near the residences of at least two U.S. diplomats and a number of American expatriates.

"I cannot help wondering whether this was meant for our American friends," one Western diplomat said.

A police statement published in the Jordanian press said investigations were underway, but it gave no further details.

In other incidents last week, a hand grenade was thrown at the downtown branch of the British Bank of the Middle East, and an arsonist set fire to the library of the French Cultural Center in Amman, destroying almost 10,000 books.

The effects of the gulf war are hitting home among Jordanians in various ways, and the impact of the war goes far beyond feelings of solidarity with Iraq.

Foreign Minister Taher Masri last week accused the allied forces of deliberately strafing four Jordanian tanker trucks transporting Iraqi oil to Jordan, destroying the vehicles and killing their drivers.

Jordan relies solely on Iraq for its petroleum supplies, and many Jordanians, whether officials or the general public, perceive U.S. insistence on the suspension of such deliveries as "intentional pressure" on Jordan or punishment for its unabashed sympathy for Iraq.

With the supply of oil from Iraq drastically curtailed, plans are being devised to begin gasoline rationing and introduce a system whereby motorists drive only on alternate days. The measures have alarmed a population fearful that its economy and freedom of movement are coming to a standstill.

"The United States has manipulated the whole world to secure its oil," commented Leila Sharaf, a Jordanian politician, "and it is not allowing us that drop of oil coming from Iraq?"