Those arrested on Saturday included Iraqis, Syrians, Egyptians and Jordanians, according to a Jordanian security official, who spoke on condition of anonymity because he was not authorised to comment publicly. He would not give the number of detainees.
Interior Minister Awni Yirfas told The Associated Press that security forces had found the launcher used to fire the three Katyusha rockets.
Police found four more rockets when they seized the launcher in a warehouse in an industrial zone on a hillside overlooking Aqaba, state TV reported Saturday. The four rockets were defused, the report said.
The newscast did not say whether anyone had been detained for Friday's attack.
The Gulf of Aqaba, a narrow northern extension of the Red Sea best known for beach vacations and Mideast summits, is bordered by Egypt, Israel, Jordan and Saudi Arabia, with the frontiers of the four countries touching or within view of one another.
Officers guard the warehouse
from which rockets were fired
Further attacks in the region would be worrisome not only because of US Navy targets in the area but also because Muslim extremists want to topple governments in Egypt, Saudi Arabia and Jordan, all longtime American allies. Egypt and Jordan have peace treaties with Israel.
The Abdullah Azzam Brigades - an al-Qaida-linked group that claimed responsibility for the bombings that killed 64 people at Sharm al-Shaikh in July and 34 people at two other Egyptian resorts in October - said in an internet statement that its members had fired the Katyushas.
Authorities said the warehouse used to launch the notoriously inaccurate rockets had been rented days beforehand by four men carrying Iraqi and Egyptian identity papers.
The security official who disclosed Saturday's arrests said an Iraqi detainee was suspected of taking part in the attack, but he cautioned against assuming the others arrested were equally involved.
A Jordanian soldier was killed and another wounded when one Katyusha flew across the bow of the USS Ashland and hit a warehouse used by the Americans to store goods headed to Iraq.
Israeli security forces inspect the
crater caused by a rocket explosion
Two more rockets were fired towards Israel. One fell short and hit the wall of a Jordanian military hospital. The other landed close to Israel's Eilat airport, lightly wounding a taxi driver.
Police said Saturday that they were searching for as many as six people - including one Syrian, Egyptians and Iraqis - who escaped in a vehicle with Kuwaiti license plates.
Security was tightened nationwide, including in the capital, Amman, which has been the target of several failed al-Qaida terrorist plots, including one using chemicals in April 2004.
Police at roadblocks were stopping cars and checking identity papers. Pictures of suspects were distributed to border checkpoints.
Although the rockets missed the USS Ashland, the Navy decided to sail both of its ships out of Aqaba bay as a precaution. They had arrived earlier in the week for a military exercise with the Jordanian navy.
Jordan is trying to determine the source of the rockets and how they were smuggled into the country.
Doug Richardson, of the London-based Jane's Defense Review, said the rockets have been widely copied from their original Russian design and modified by many countries, including those in eastern Europe and China.
Iran and Hizb Allah would be "potential sources" of the weapon, he said in a telephone interview.
In Lebanon, a Hizb Allah official declined to comment when asked about the group's involvement.
In Syria, Elias Murad, chief editor of Al-Baath newspaper, mouthpiece of the country's ruling Baath Party, said attempts to involve Damascus were "ridiculous because Katyusha rockets exist in two-thirds of the world".
In Iraq, Katyusha rockets have been used in attacks against US military installations.