The missile struck in the roadway next to the InterContinental hotel at the northern edge of the city. Across the border, at the northern entrance to the Israeli resort of Eilat, the police found the remains of another rocket, leading to suspicions that the one that struck Aqaba had been aimed at its neighbor but veered off course. There were no immediate claims of responsibility.

The missile was identified as a Grad derivative with a range of about 25 miles. Such rockets are notoriously inaccurate.

Rocket attacks are not unknown in this area, but it is difficult to pinpoint a source. In 2005 a Katyusha rocket attack on two American warships in Aqaba’s waters missed the intended target but killed a Jordanian soldier. In April, rockets were fired toward the two resorts; one hit a Jordanian warehouse. It too was identified as a Grad-type rocket.

The two resorts lie more than 100 miles from Gaza, a focal point of tensions between Israel and the Palestinians, and a source of persistent rocket fire. Over the last few days, militants there broke a long lull — even as moves were made toward direct Palestinian-Israeli peace talks — firing rockets that struck the Israeli coastal city of Ashkelon and an Israeli college near the Gaza border. Israeli war planes bombed several sites, killing a commander of Hamas’s military wing.

The resorts are located in a delicate area — near the northwestern edge of Saudi Arabia and at the northern tip of the Red Sea, where Israel adjoins the only two Arab countries with which it has signed peace treaties, Jordan and Egypt.

Jordanian officials, while insisting that the rocket had come from beyond its borders, refused to be much more specific. Maj. Gen. Hussein Majali, the director general of public security, said that an examination of the angle of impact showed that the rocket had “definitely come from the southwestern side of Aqaba.”

To the southwest of Aqaba lies the Red Sea and Egypt’s Sinai Peninsula. A small corner of Saudi territory falls to the southwest as well.

In Israel, the assumption was that the rockets were fired from Egyptian territory. Israel has long warned its citizens to avoid the Sinai because of the threat of attacks or kidnapping by Islamic militants. Militants hostile to Israel as well as to Egyptian and Jordanian authorities and the West have bombed Sinai resorts in the past. Eilat was struck by a suicide bomb in 2007, with the attacker entering Israeli territory from the Sinai.

But Egyptian officials denied Monday that the rocket had been launched from their territory. Gen. Muhammad Shousha, an official in the southern Sinai, said in a telephone interview that the rocket had not come from Egypt, but that security “procedures” were under way “in case there is anything new to know.”

A Polish tourist, Piotr Dudojc, said that he had been sleeping on the roof of a hotel in Aqaba when he was awakened by two explosions.

“I looked out at the city and I saw the smoke and took two photographs,” he said.

He added: “I went to have a look but I couldn’t see anything because of all the soldiers and police.”

At the sand-colored InterContinental hotel in Aqaba, Jordanian security forces armed with automatic weapons sealed off King Hussein bin Talal Street with black and yellow tape as fire department vehicles and ambulances arrived. The street was littered with glass next to two taxis. One was badly burned, and the other had also suffered damage.

Maysa Liswi, 45, an interpreter from Amman, was staying at the InterContinental while attending a six-day conference at which, she said, American instructors were training Jordanians in how to detect radioactive cargo arriving at the port.

“We heard something very loud,” said Ms. Liswi. “We didn’t know what it was. I thought it was a truck explosion.”

Hotel guests appeared to carry on, Ms. Liswi said, though the conference she was attending was canceled.

Stephen Farrell reported from Aqaba, and Isabel Kershner from Jerusalem. Reem Makhoul contributed reporting from Aqaba, and Mona El-Naggar from Cairo.