Abu Musab al-Zarqawi's group in Iraq has claimed responsibility for the weekend rocket attack that narrowly missed US warships anchored at the Red Sea port city of Aqaba in Jordan.
Al-Zarqawi's al-Qaida-linked group on Tuesday was the second to claim responsibility for the rocket attack, but the authenticity of the statement, signed by group spokesman Abu Maysara al-Iraqi, could not be verified.
The first claim was issued by the Abdullah Azzam Brigades shortly after the Katyusha rockets were fired from a hilltop warehouse, overlooking Aqaba and its port.
The al-Zarqawi group explained the delay in issuing its claim by saying it waited five days "so that the brothers could finish retreating".
Jordanian officials were not immediately available for comment on the claim, but investigators have said the rocket assault carried the hallmarks of al-Qaida.
Late on Monday, Jordan announced it had arrested a Syrian, one of four men allegedly involved in the attack.
The captured man's two sons and the Iraqi leader of the group were believed to have escaped to Iraq, officials in the Jordanian capital said.
The Jordanian announcement said the four were part of an Iraq-based organisation, which the government did not identify.
Rockets missed two US naval
ships in Aqaba
The Syrian arrested in the attack was identified as Mohammed Hassan Abdullah al-Sihly.
He was assisted by his two sons, who also hailed from the northern Syrian city of Hama, although the father was said to live in Amman.
The fourth member of the team and its leader was Mohammed Hamid Hussein, an Iraqi.
A Jordanian government official said the rocket launch was triggered by a timing device that allowed al-Sihly's sons and the Iraqi to escape into Iraq hours before the attack.
The official did not explain why al-Sihly did not manage to flee.
In the Friday attack, the most serious against the US Navy since the 2000 bombing of the USS Cole in Yemen, one rocket flew across the bow of a US amphibious assault ship and crashed into a warehouse, killing a Jordanian soldier.
Another missile landed near a Jordanian hospital, and a third hit a taxi on the outskirts of an Israeli airport, but did not explode.