How the guests in hotel room 1808 may have struck

By Sara Webb and Telly Nathalia

JAKARTA (Reuters) - The bombers that attacked two luxury hotels in Indonesia's capital on Friday checked into one of their targets a couple of days before, posing as paying guests to crack tough security cordons usually in place.

Eight people were killed and dozens wounded when two bombs exploded within minutes of each other at the JW Marriott and Ritz-Carlton hotels in the heart of Jakarta's business district.

After an incident-free four years following a spate of deadly bombings blamed on the al-Qaeda-linked Jemaah Islamiah (JI) group, Friday's attacks have shaken faith in the effectiveness of security at hotels and other possible targets.

It took years for Bali to recover from a deadly 2002 attack on its main tourist strip that killed 202 people, mostly foreigners.

Police said the Marriott device was planted by people who had checked in as guests and had probably assembled the device in their room.

"Room 1808 had become their post since the 15th," National police chief General Bambang Hendarso Danuri told a news conference.

While he wouldn't immediately draw a connection to JI, Danuri said the bombs were made in the same way as an unexploded device found recently in Central Java.

Local media said that bomb was found in a house thought to be owned by the father-in-law of Noordin Top, a senior JI leader who remains at large.