Authorities in Taiwan are honing in on the possible location of two missing Australian-Singaporean nationals, after emergency service workers established their last known whereabouts.
Neo Siew Choo and Sim Hwee Kok had been staying in Haulien City but, on the morning of the earthquake boarded a bus that went inside the Taroko National Park, on the island's eastern coast.
The mountainous national park, famed for its natural beauty, is at the quake's epicentre, and suffered extensive landslides when the devastating 7.2 magnitude earthquake struck.
On Saturday, search and rescue teams found the bus and its driver, who was safe but stuck further inside the national park at a recreation area.
Footage from the bus, released by Taiwan's National Fire Agency, shows the couple getting off at Shakadang Trail, a well-known hiking spot. The pair have not been seen or heard from since.
Six other people were reported missing on the same trail. Three of them have been found deceased.
The captain of the Special Search and Rescue Team, Chen Yi-feng, said teams would continue to focus on an area of the trail that had collapsed.
"We're suspicious that they're there, but of course, we can't confirm," he told local reporters.
Hundreds were stranded inside Taroko National Park due to extensive landslides blocking road and tunnel access, but have since been rescued.
Authorities in Taiwan have described Neo Siew Choo and Sim Hwee Kok as married, and as Australian-Singaporean dual nationals.
On Monday, Australia's Department of Foreign Affairs (DFAT) said it was providing consular assistance to the family of two Australians reported missing.
Neo Siew Choo and Sim Hwee Kok are the last foreigners known to be missing since the quake.
Two other Australians are known to be among 71 foreigners rescued after the earthquake.
Rescue efforts continue
The death toll rose to 13 after a third victim was found on the trail, with more than 1,100 people reported as injured. The extent of the injuries has not been made clear.
More than 400 people remained stranded three days after the quake in locations cut off by damage. Most were at a hotel in Taroko park.
Hundreds of aftershocks have struck the area since Wednesday morning, including a magnitude-5.2 earthquake shortly before noon on Saturday.
[Epicentre map]The demolition of a building that is leaning precariously after an earthquake in Taiwan was also halted on Saturday because of the aftershocks that made it lean even more, media reports said.
The red building, about 10 stories tall and inclined over a street in the city of Hualien, has become an iconic image of the earthquake.
The relatively low number of deaths from the powerful quake has been attributed to strict construction standards and widespread public education campaigns on the earthquake-prone island.
The quake was the strongest to hit Taiwan since a magnitude 7.7 earthquake in 1999 that killed 2,400 people.
ABC/wires
