A strong undersea earthquake has struck off the Indonesian island of Sulawesi. The authorities initially advised residents to leave coastal areas as a precaution - but later said there had been no tsunami. Last week a 7.7-magnitude earthquake off the southern coast of Java island triggered a tsunami that killed more than 650 people. There are no reports of damage so far from the latest quake, which Indonesian officials said had a magnitude of 6.6.
Indonesian President Susilo Bambang Yudhoyono has vowed to speed up efforts to build an early warning system planned after the 2004 Asian tsunami. His government has come under fire over why no warning was given to local people in last week's tsunami.
