New Delhi: Two giant quakes struck off the coast of Aceh in Indonesia`s Sumatra islands, triggering a wave of panic and tsunami alerts across 28 countries around Indian Ocean, which were lifted after few hours.
Memories and fears of 2004 Tsunami came alive when a massive 8.6 magnitude quake, initially measured to be 8.9 on the Richter scale, hit off the west coast of Northern Sumatra at 08:38 GMT. Panic stricken people rushed out on the streets calling "God is Great."
The depth of the quake was reported to be 22.9 kilometres.
What followed was a series of strong aftershocks, including a major 8.2 aftershock that struck just over two hours later, at 10:43 GMT.
Indonesian President Susilo Bambang Yudhoyono said there were no immediate reports of casualties or damage in Aceh.
The Pacific Tsunami Warning Centre issued fresh tsunami warnings for the entire Indian Ocean region after the aftershocks which were lifted after five hours.
Authorities in Indonesia said there were reports of sea-levels rising off Aceh, but by less than a metre (3.3 feet).
Residents were seen crying in Aceh, where memories of a 2004 tsunami that killed 170,000 people in the province alone, are still raw. People poured from their homes searching frantically for separated family members.
Indonesia`s disaster management agency said power was down in Aceh province and people were gathering on high ground as sirens warned of the danger.
"The electricity is down, there are traffic jams to access higher ground. Sirens and Koran recitals from mosques are everywhere," said Sutopo, spokesman for the agency.
Several countries, including Thailand, Indonesia, Sri Lanka and India, issued their own tsunami warnings and people near the coast in six Thai provinces were ordered to evacuate to higher ground. Authorities shut down the international airport in the Thai beach resort province of Phuket.
India later withdrew the tsunami warning, saying there was no likelihood of tsunami tidal waves being formed anywhere in the Indian Ocean region.
India had initially issued tsunami alert for its coastal regions, including the Andaman and Nicobar Islands, Tamil Nadu, Karnataka and Andhra Pradesh, after tremors were felt in its southern and northeastern states.
The quake was also felt in Dhaka, Bangladesh, where many people in the city`s commercial Motijheel district left their offices and homes in panic and ran into the streets. No damage or causalities were reported.
In Male, the capital of the Maldives, buildings were evacuated.
Sri Lanka issued a tsunami warning across the island and the disaster management centre asked residents on the coast to move inland to avoid being hit by any large waves.
In the Sri Lankan capital Colombo, nervous crowds gathered on the streets after the strong quake.
The initial quake was a strike-slip, not a thrust quake, according to experts. In a strike slip quake, the earth moves horizontally rather than vertically and doesn`t displace large volumes of water.
They were still analyzing the aftershock.
"When I first saw this was an 8.7 near Sumatra, I was fearing the worst," Roger Musson, seismologist at the British geological survey who has studied Sumatra`s fault lines, noting one of the initial reported magnitudes for the quake. "But as soon as I discovered what type of earthquake it was, then I felt a lot better."
The first tremor was felt in Malaysia, where it caused high-rise buildings to shake for about a minute, and in Singapore, Thailand, Bangladesh and India.
A giant 9.1-magnitude quake off the country on December 26, 2004, triggered a tsunami in the Indian Ocean that killed 230,000 people, most of them in Aceh.
Last year, a 9.0-magnitude earthquake caused a tsunami and nuclear disaster in Japan, killing some 19,000 people.
(With agencies’ inputs)