The horrific bombings in Bali on Saturday left scenes of death and destruction which have, sadly, become all too familiar in recent years. They serve as a grim reminder that international terrorism continues to pose a grave threat to the world. These latest attacks were especially cruel. It is less than three years since this idyllic Indonesian island, popular with foreign tourists, was last targeted by bombers, with similarly devastating consequences. The blasts came just ahead of the third anniversary of the 2002 bombings, which claimed 202 lives. The killings on Saturday will bring back painful memories for people in Hong Kong, as 11 of our residents were among those who died in the 2002 bombings. This time, the attacks were not on quite the same scale. But that is of little consolation. Many have been killed and more than 100 injured in bombings calculated to cause as much bloodshed as possible. There are many similarities between Saturday's attacks and those of 2002. They were carried out in places popular with foreign tourists. Many of the dead and wounded had come to Bali from overseas. There are victims from Japan, South Korea, Australia, France and the US. This demonstrates the aim of the terrorists - to target foreign tourists. It also underlines the fact that the terror threat is one faced by all nations. No wonder the attacks have been condemned by governments around the world. Most of the victims, however, were Indonesian, presumably regarded by the callous bombers as collateral damage. The hunt is now on for the culprits. It is not yet known who was responsible. But suspicion will fall on the militant Islamic group Jemaah Islamiah (JI), linked to more than 50 bombings since 1999. It was responsible for the Bali attacks in 2002 and is believed to have also carried out the bombing of the JW Marriott hotel in Jakarta in 2003 and the Australian embassy, also in Jakarta, last year. There is evidence to suggest that the latest blasts are the work of this group, believed to have ties to Osama bin Laden's al-Qaeda network. Experts believe that only JI would be capable of perpetrating bombings of this kind in Indonesia. If JI is behind the bombings, a blow will have been struck against the Indonesian government's efforts to crack down on the group. The Bali bombings in 2002 prompted an attempt by the government to root out terrorists in the world's most populous Muslim country. Since then, there have been many arrests. Some 40 or 50 suspects have been convicted by Indonesian courts of offences related to the Bali and Jakarta bombings. Five have been sentenced to death. JI has lost some of its leaders, with alleged spiritual chief Abu Bakar Bashir serving a 30-month prison term for conspiracy charges connected with the Bali blasts in 2002. There had been hopes that these efforts had broken JI and rendered it incapable of mounting another deadly attack. Such hopes now appear to have been overly optimistic and efforts must now be stepped up to rein in JI. Two of its most dangerous members, a bomb maker and chief recruiter, are still at large and believed to be in Indonesia. They narrowly escaped capture in a police swoop there last year. Indonesia has, so far, resisted calls to outlaw the organisation. It will now come under renewed pressure to do so. Bali's economy depends on tourism. It had only just recovered from the 2002 blasts. Now it faces another slump. The impact on tourism might, however, not be as pronounced as in 2002. Since then, there have been similar attacks in many other parts of the world, including Madrid and London. The bombings remind us that there is no room for complacency. There is a need for the greatest vigilance, closer co-operation between states, and - above all - resolve, if the world is to combat the threat of international terrorism.