DUBAI, United Arab Emirates — The Saudi man who blew himself up inside a Shiite mosque in Kuwait last week flew into the country after transiting through nearby Bahrain and had no background suggesting he planned to carry out a terrorist attack, according to Gulf officials.

The details released by Saudi and Bahraini authorities paint a fuller picture of the suicide bomber in Friday's attack that killed 27 worshippers and wounded more than 200 in one of Kuwait City's most prominent Shiite mosques. A branch of the Islamic State group claimed responsibility for the bombing.

The blast — which struck within hours of deadly attacks in Tunisia and France — has rattled largely stable Kuwait. The small, oil-rich country, ruled by a Sunni monarchy and with a sizable Shiite minority, has mostly avoided the sectarian violence rocking other parts of the region.

Kuwaiti officials have identified the bomber as Fahad Suleiman Abdulmohsen al-Gabbaa, a Saudi man in his early twenties who landed in the country just hours before the attack.

Bahrain's Interior Ministry said Monday that al-Gabbaa arrived in that island nation on a Gulf Air flight from the Saudi capital, Riyadh, at 10:40 p.m. Thursday. He remained in transit for two and a half hours before boarding a connecting flight to Kuwait.

Saudi Arabia's Interior Ministry said the bomber had no record with security forces or any background indicating terrorist activities. It confirmed he left the kingdom Thursday bound for Bahrain.

An audio message accompanied by two still photos that was posted online and promoted by Twitter accounts affiliated with the Islamic State group purports to be a final message from al-Gabbaa.

A caption below the clip calls the bomber a "soldier of the caliphate" and identifies him by the nom de guerre of Abu Suleiman al-Muwahhed.

In the message, the speaker vows to pursue jihad against his enemies, particularly Shiites in Kuwait, saying "we are on the lookout for you." He also addresses Islamic State group's leader, Abu Bakr al-Baghdadi, telling him to "be patient and swear to God that we are with you."

IS militants consider Shiites to be heretics and are fighting Iranian-backed Shiite militias in Iraq and Syria.

The group's Najd Province offshoot, which said it was behind the Kuwait mosque attack, has claimed two attacks on Shiite mosques in Saudi Arabia in late May. The branch's name refers to the central region of Saudi Arabia.

Associated Press writer Maamoun Youssef in Cairo contributed to this report. Follow Adam Schreck on Twitter at