More than 1,000 rescue workers including troops are searching for 13 people missing as a result of the earthquake.
"In this case, it's a very mountainous area and if the roads are cut, even if you call out the troops, you can't get in," said Masaaki Sakakibara, a military official in charge of co-ordinating rescue operations in Kurihara near the epicentre.
"We are very lucky this time because the weather is good, so we can use helicopters. The roads here are very narrow and this limits access."
The 7.2 magnitude earthquake struck on Saturday morning in the prefectures of Miyagi and Iwate, a sparsely populated, scenic region around 300km north of Tokyo.
The force of the earthquake carved sections out of the mountains and brought down trees.
Roads were cut off by landslides, and bridges buckled and broke.
The earthquake also caused up to 14.8 litres of water to leak out from a pool in a warehouse that kept radioactive waste at Tepco's Fukushima Daini nuclear power plant.
But an official at the plant said that "no water" leaked outside the warehouse and Tepco's two nuclear plants in Fukushima, including Fukushima Daini, were operating normally.
Sendai, the nearest large city to the earthquake's epicentre, appeared to be unaffected by the tremor.
More than 260 aftershocks had jolted the area by Sunday morning, and officials warned there could be strong quakes to come.
Japan's meteorological agency warned of the earthquake just before 8:43am [GMT] and NHK, Japan's national broadcaster, flashed the alert moments before the quake struck.
But the warning came too late for areas near the epicentre and the Yomiyuri Shimbun, a Japanese daily, carried an article on Sunday saying the event "highlighted technological shortcomings" in the country's early-warning system.
But the paper said the system "proved useful in preventing damage in some cases ... in areas further than 40km from the epicenter".
Japan accounts for about 20 per cent of the world's powerful earthquakes and has built an infrastructure intended to withstand the impact of tremors.