By Agence France-Presse
The 6.9 magnitude tremor, which triggered panic among tourists and locals on Sunday evening, was also felt on the neighbouring island of Bali, one of Southeast Asia's leading tourist destinations.
Nugroho said an initial tsunami warning which was later cancelled had sparked terror as residents scrambled to reach safer ground.
"People were panicking... especially because of the early tsunami warning," he said.
Memories of the devastating 2004 tsunami which claimed 168,000 lives in Indonesia remain raw in the vast archipelago nation.
Most of the victims in the latest disaster died in mountainous northern Lombok, away from the main tourist spots on the south and west of the island. Thousands of people were evacuated to outside shelters.
Lombok's beaches and hiking trails draw holidaymakers from around the world.
The death toll jumped from 37 hours earlier as the scale of the destruction began to emerge overnight.
The US Geological Survey said the shallow quake hit northern Lombok just 10 kilometres underground and was followed by two further secondary quakes and nearly two dozen aftershocks.
'Everyone ran out of their homes'
Rescue officials said much of the damage had hit Lombok's main city of Mataram.
Residents of the city described a strong jolt that sent people scrambling to get out of buildings.
"Everyone immediately ran out of their homes, everyone is panicking," Iman, who like many Indonesians has one name, told AFP.
Electricity was knocked out in several parts of the city and patients were evacuated from the main hospital, witnesses and officials said.
Singapore's Home Affairs Minister K. Shanmugam, who was in Lombok for a security conference when the earthquake struck, described on Facebook how his hotel room on the 10th floor shook violently.
"Walls cracked, it was quite impossible to stand up," he said.
Despite the tsunami warning being cancelled, seawater poured into two villages, senior disaster agency official Dwikorita Karnawati told local television.
In the neighbouring resort island of Bali people could be heard screaming as locals and tourists ran onto the streets.
Bali's international airport suffered damage to its terminal but the runway was unaffected and operations had returned to normal, disaster agency officials said.
Facilities at Lombok's main airport were also unaffected, although passengers were briefly evacuated from the main terminal.
The tremor came a week after a shallow 6.4-magnitude quake hit Lombok, killing 17 people and damaging hundreds of buildings.
It triggered landslides that briefly trapped trekkers on popular mountain hiking routes.
Indonesia, one of the most disaster-prone nations on earth, straddles the so-called Pacific "Ring of Fire", where tectonic plates collide and many of the world's volcanic eruptions and earthquakes occur.
In 2004 a tsunami triggered by a magnitude 9.3 undersea earthquake off the coast of Sumatra in western Indonesia killed 220,000 people in countries around the Indian Ocean, including 168,000 in Indonesia.