DUBAI, United Arab Emirates -- The Saudi man who blew himself up inside a Shiite mosque in Kuwait managed to slip out of his home country without raising any red flags and board a commercial flight transiting nearby Bahrain less than 24 hours before the deadly attack.
The details of the bomber's final hours, released by regional authorities, highlight the growing involvement of undetected Islamic State sympathizers on the Arabian Peninsula and the threat they pose to countries closer to home than the battlefields of Iraq and Syria.
Friday's blast in one of Kuwait City's most prominent Shiite mosques killed 27 worshippers and injured more than 200. It followed two suicide bombings in neighbouring Saudi Arabia just weeks earlier, raising fears of more attacks to come in the Gulf.
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.
The bombing -- which struck on the same day as deadly attacks in Tunisia and France -- has rattled Kuwait. Violence is rare in the small and stable OPEC nation, which is ruled by a Sunni monarchy and has a sizable Shiite minority. Kuwait also regularly hosts American soldiers and other Western troops.
It is unclear how much help al-Gabbaa had inside Kuwait and when and how he obtained his explosives. Kuwaiti police have arrested at least two people in connection with the attack.
One is a man who authorities allege drove al-Gabbaa to the mosque. Another, according the Kuwaiti Interior Ministry, is a known follower of "fundamentalist and deviant ideology" who housed the driver.
Gulf citizens can travel easily among the six-nation Gulf Cooperation Council bloc, making it simple for al-Gabbaa to exploit the region's extensive transportation links.
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 IS 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 IS 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 last month pledged to expel all Shiites from the Arabian Peninsula.
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.
In an apparent response to the threat, Bahraini officials this week met with senior Sunni and Shiite religious leaders to discuss efforts to secure places of worship, including closing mosques after each prayer session to make it easier for caretakers to monitor them.
The move follows unsubstantiated threats circulated on social media claiming that Bahrain will be the IS group's next target on Friday.
The threats were attributed to IS operative Turki al-Binali, a Bahraini preacher who has emerged as one of the extremist group's leading ideologues. Bahraini authorities stripped the preacher's citizenship along with that of 71 others in January.
