Wellington, March 5 : The New Zealand government on Friday downgraded a tsunami warning and said that "all people who evacuated can now return" after three massive offshore quakes jolted the country's North Island one after another overnight. Earlier in the day, the National Emergency Management Agency urged locals to move immediately to the nearest high ground, out of all tsunami evacuation zones, or as far inland as possible and not to stay at home until further message from the authorities, following an 8.1-magnitude earthquake at about 8.30 a.m. near the Kermadec Islands, Xinhua news agency. Another 7.4-magnitude quake jolted Raoul Island, the largest island of the Kermadec Islands, at 6.41 a.m. Large coastal areas including the north and the east part of the North Island were affected. Another massive 7.1-magnitude earthquake struck at 2.27 a.m. local time, about 95 km east of Te Araroa, the far northeast point of the North Island. It caused "severe" shaking and sparked tsunami warnings, reported GeoNet NZ. The quake was defined as "terrifying" and "biggest one" by locals. Jolts were felt throughout much of the country. Trains were halted and lines across eastern parts of the North Island closed ahead of track inspection for possible quake damage. New Zealand Prime Minister Jacinda Ardern posted on Instagram: "Hope everyone is ok out there." Last week, New Zealand marked the 10th anniversary of the 6.3 magnitude earthquake that destroyed parts of Christchurch, killing 185 people. Earthquakes occur frequently in New Zealand as the country is situated in the collision zone between the Indo-Australian and Pacific tectonic plates, part of the Pacific Ring of Fire, where many earthquakes and volcanoes occur. /IANS