JAKARTA, April 12 (UPI) -- At least five people died after two major earthquakes struck off the coast of Indonesia's Sumatra Island, officials said Thursday.
The National Disaster Mitigation Agency said three people died of heart attacks and two others died of shock after Wednesday's 8.6-magnitude and 8.2-magnitude earthquakes, CNN reported.
Indonesia's Meteorology, Climatology and Geophysics Agency said at least 25 major aftershocks, ranging in magnitude from 5.1 to 8.1, have been recorded, Antara said.
Tsunamis were reported in the towns of Sabang and Meulaboh, and in West Sumatra's Nias Islands, with heights reaching about 3 feet, officials said. Tsunami alerts had been issued for the entire Indian Ocean.
There were no immediate reports of significant damage.
Meteorology, Climatology and Geophysics Agency Dadang Permana told the Antara news agency there was some concern Wednesday's quakes could touch off more frictions on the Indoaustralian tectonic plate that could lead to more strings of quakes along the western Sumatra coast.
"Thus people living along western Sumatra coasts, starting from Aceh, North Sumatra, West Sumatra, Bengkulu and Lampung must stay alert," he said.
