AMMAN, Jordan - Al-Qaida in Iraq claimed Tuesday it had reached across the border into Jordan again to carry out the weekend Katyusha rocket attack that narrowly missed a U.S. warship in the Red Sea port of Aqaba.

Jordanian authorities, after capturing a Syrian who was labeled a prime suspect in the attack, said it appeared a number of others had fled to Iraq.

The Internet statement by al-Qaida in Iraq, lead by Jordanian-born Abu Musab al-Zarqaw, was the second claim of responsibility and was signed by group spokesman Abu Maysara al-Iraqi. It was impossible to authenticate the claim.

Al-Zarqawi is a key figure in the insurgency in Iraq and the second most-wanted terrorist on the U.S. list after al-Qaida founder Osama bin Laden.

Al-Qaida in Iraq said it had not issued its claim until five days after the attack "so that the brothers could finish retreating."

"God has enabled your brothers in the military wing of the al-Qaida in Iraq to plan for the Aqaba invasion a while ago," the statement said. "After finishing the preparations and deciding on the targets, your brothers launched the rockets."

Jordanian security officials declined to speculate who was behind the attack, although some officials had previously noted it bore the hallmarks of al-Qaida.

The first claim of responsibility came from the Abdullah Azzam Brigades shortly after the Katyusha rockets were fired from a warehouse window on a hill overlooking Aqaba.

Al-Sihly's two sons and the alleged Iraqi leader of the group, Mohammed Hamid Hussein, were believed to have fled to Iraq, the government said, adding that the rocket launch was controlled by a timing device.

That, it said, allowed al-Sihly's three accomplices time to flee the country before the rockets were fired. There was no explanation why al-Sihly did not escape.