By Ashraf Fouad
KUWAIT, Oct 13 (Reuters) - Kuwait and its ally the United States launched a joint inquiry on Sunday to determine how cooperation between them fell apart after the killing of a U.S. Marine in a "terrorist" attack.
A team from the U.S. Federal Bureau of Investigation arrived in Kuwait earlier in the day to take part in the joint inquiry, a U.S. embassy source said.
But Kuwait's government stressed following its weekly meeting on Sunday the attack "will never impact the deep friendly and historical ties with the United States".
Interior Minister Sheikh Mohammad Khaled al-Sabah told a news conference in Kuwait on Saturday night that confusion reigned for four to five hours after Tuesday's attack, which led to the arrest of a cell with indirect ties to al Qaeda.
Kuwait said it had foiled further attacks against Western targets in the oil-rich country by arresting suspects, who included several members of Kuwait's al-Kandari tribe.
Anas al-Kanadri of al-Kandari was the ringleader, Kuwait said. His tribe on Sunday condemned acts "by some misled youths to enforce the law of the jungle and claim it is Islam,... which calls for coexistence with others even of different faiths".
The tribe also stressed its gratitude for the U.S. role in the 1991 Gulf War.
One Marine was killed and another wounded in Tuesday's attack during training on a Kuwaiti island. Marines killed the two attackers, later found to have trained in al Qaeda camps in Afghanistan, and immediately arrested 31 people in the area.
Kuwait said on Sunday in a statement sent to Reuters: "The Kuwaiti people will never forget the decisive (U.S.) stand in the worst of times...and it (the United States) is still keeping to its word to deter the threats of the Iraqi regime and its evil intent."
Sources said Kuwaiti police were not allowed to take charge of the situation for a few hours after the attack and there was a dispute over which country's officials were in charge.
Sheikh Mohammad called the joint inquiry very important, saying: "We will see the faults -- why we were not informed about their (Marines') presence after they finished the exercise, why we (the Kuwait police) were late to arrive."
The minister said it was necessary to be frank and tackle the problems because there could be important developments in the region, a reference to a possible war against Iraq.
U.S. officials in Kuwait could not say if Washington would allow Marines involved in the attack to testify in a Kuwaiti criminal court, a possible Kuwaiti request.