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-Zarqawi, 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.”

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

Tuesday night Interior Minister Awni Yirfas said: “The investigation shows a link to al-Zarqawi.” He also said Jordan was studying the possibility of seek the extradition of those who fled to Iraq.

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.

Late Monday, the Jordanian government announced the capture of Mohammed Hassan Abdullah al-Sihly, the Syrian whom it called the “main element” in a four-man terror cell affiliated with an Iraq-based militant group it did not name.