Quoting from the article:

No-one has yet claimed responsibility for the attack.



Indonesian officials have denied that militants linked to al-Qaeda are active in the country.

However, authorities in Malaysia and Singapore have claimed that members of a group known as Jemaah Islamiyah - said to be seeking to set up an Islamic state in South East Asia - are based in Indonesia.



Because of my weird work schedule, I was awake and listening to the BBC World Service about the time this story was posted on their website. No mention was made of suspect organizations or ' claimed responsibility' in the audio coverage. Note the hedging in the written version: "authorities have claimed"; "said to be". Speculation, pure and simple.

But that was two hours ago. We shall see. Keep in mind, though - there is no logic to any assumption that militant Islam is monolithic, nor that all terrorists are automatically part of, or even allied with, alQaeda.