Emergency relief staff with World Vision are on standby following two large earthquakes off the coast of Indonesia.

An 8.6-magnitude earthquake off the coast of Aceh province was followed a few hours later by another quake measuring 8.3.

Geoff Shepherd, World Vision Humanitarian and Emergency Affairs Director, Asia Pacific, said communities had been alerted and that it was the aid agency’s priority to secure the safety of children and the vulnerable.

A tsunami warning put out following the quakes has now been partly lifted, the Pacific Tsunami Warning Center said.

The BBC said there were no immediate reports of damage or casualties.

The last time an earthquake of such size hit Aceh was in 2004. It triggered a tsunami that swept across the coasts of countries bordering the Indian Ocean and killed more than 230,000 people.

Billy Sumuan, Humanitarian and Emergencies Director for World Vision in Indonesia, said: “Everyone is in a state of nervousness. We have been in touch with our project staff in Aceh and they reported that everyone was running for higher ground.

“People in Aceh remember the tsunami like it was yesterday. It has been burned into our minds because so many people lost loved ones and whole towns were literally wiped off the face of the earth.

“No one who lived through that takes these warnings lightly.”

World Vision has a permanent team of emergency responders ready to deploy in Indonesia and other countries bordering the Indian Ocean. Its staff in Sri Lanka, Nepal, Singapore, Malaysia and India have reported tremors and some teams have moved to higher ground.

The aid agency said it was monitoring the situation closely.

Operations Director Charles Asinaga said: “There was a real sense of panic after the quake struck. People crowded the streets to flee the coast.

“The telephone lines are still clogged with people phoning loved ones. It’s very difficult to get information.

“We are waiting for news from the cities on the coastal area, including southern parts of the province like Meulaboh, and the small islands near the epicentre.”