JAKARTA: All 22 of the early-warning buoys Indonesia deployed after the 2004 tsunami disaster were inoperable when a massive undersea earthquake struck off the coast on Wednesday, a National Disaster Mitigation Agency official said.

The 7.8 magnitude quake did not trigger a tsunami, and there were no deaths and no major damage, but it did expose gaps in the systems put in place to prevent a disaster similar to the Indian Ocean quake that killed more than 200,000 people 11 years ago.

In addition to the malfunctioning of buoys designed to warn of massive waves, authorities said there were not enough evacuation routes or shelters in Padang, a Sumatra island port city of around one million people that felt the quake.

“There was definitely panic last night, that cannot be denied,” said Zulfiatno, the head of the disaster management agency in Padang who uses only one name, adding that shelters had the capacity to only hold around 200,000 people.

“But the situation has improved from previous years. People have started to understand how to evacuate safely.”

The 9.15 magnitude quake of December 2004 opened a fault line deep beneath the ocean, triggering a wave as high as 17.4 meters that crashed ashore in more than a dozen countries to wipe some communities off the map in seconds.

Indonesia straddles the so-called “Pacific Ring of Fire,” a highly seismically active zone, where different plates on the earth’s crust meet and create a large number of earthquakes and volcanoes.

Soon after that disaster, Indonesia introduced a sophisticated early warning system using buoys, sea-level gauges and seismometers that can send alerts to countries’ tsunami warning centers within 10 minutes of a quake.

Although there were some strong aftershocks on Thursday, normal life largely resumed at daybreak in Padang.

There were 11 aftershocks during the night following the main quake, but authorities called for calm as they had diminished in strength.

“We do not believe that there will be an earthquake of greater strength,” the National Meteorological Agency said on its Twitter account. “And so residents are urged to keep calm and not be taken in by rumors.”