A massive earthquake measuring 8.7 on the Richter scale hit Indonesia and the surrounding regions on 11 April, following which tsunami warnings have been issued for all nearby coastal countries.

The quake was in roughly the same area as a 26 December, 2004, quake of 9.1 magnitude which sent huge tsunami waves crashing into Sumatra. More than 150,000 people were killed in that natural disaster. The 2004 tsunami killed about 230,000 people across 13 countries in the Indian Ocean region, including Thailand, Sri Lanka and India.

According to Indonesia's disaster management agency, electricity supply was down and there were traffic jams as people sough higher ground for safety from the tsunamis that are supposed to follow. People have sought recourse in prayer and spiritual activities, with sirens and Koran recitals from mosques sounding everywhere, the agency added.

So far, the Pacific Tsunami Warning Centre has issued a tsunami watch for 28 countries including Indonesia, India, Sri Lanka, Australia, Myanmar, Thailand, Maldives, Britain, Malaysia, Mauritius, Pakistan, Iran, Madagascar and Singapore.

India has also issued tsunami warnings after the massive earthquake hit the eastern coast of the country including cities like Chennai and Kolkata. India's tsunami warning center said waves measuring up to six metres were expected along parts of its eastern coast, which was heavily hit by the 2004 tsunami. Smaller waves were expected to hit the remote Andaman and Nicobar islands, where evacuation drills are being ordered.

Here is a liveblog covering the post-quake developments and possible tsunami threat.