The nine Australians on board a tourist vessel near the shores of earthquake-hit Sumatra, Indonesia were declared safe, the Australian Department of Foreign Affairs and Trade said.

In a statement, the government agency said those aboard the ship MV Southern Cross were brought ashore. They were not aware that an earthquake and tsunami had taken place, it added.

A day after the 7.7-magnitude earthquake struck off Sumatra, Indonesia, triggering a tsunami and killing at least 112 people, officials said relief organizations are struggling to reach those in need, CNN has reported.

Because of the myriad of islands comprising the nation of Indonesia, gathering of information came in trickles. Initial reports said the quake triggered a tsunami that reached as high as six meters in West Sumatra.

CNN quoted Henri Dori Satoko, head of the Mentawai Islands parliament, whor reported that at least one village with a population of about 200 people was swept away. only 40 people from the village were recovered as of press time.

Mentawai Islands, a popular surfing destination, is believed to be the hardest hit. Reports said Pagai Island is inaccessible.

A program manager for World Vision in Padang said in a CNN report: "We want to get help to these children and their families as quickly as possible, but it's still too dangerous to reach the island by boat."

Large waves and sea debris prevents rescue efforts in some areas led by the Indonesian Red Cross.