Indonesian officials say all 22 tsunami warning buoys installed near vulnerable islands failed to work when a powerful earthquake struck off the coast of Sumatra.

Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho said Thursday that the buoys were inoperable because of vandalism or a lack of funds for operation and maintenance.

A magnitude-7.8 earthquake hit parts of Sumatra and small islands in western Indonesia on Wednesday evening, sending thousands of islanders rushing to high ground but causing no major damage or deaths. It was centered 659 kilometers (409 miles) from the town of Muara Siberut.

German and Indonesian scientists began installing warning buoys off Sumatra island a year after a magnitude-9.1 quake in 2004 triggered a tsunami that killed 230,000 people in a dozen countries.