He has said several times that the number of deaths will increase.
Officials said about three-quarters of Lombok's rural north had been without electricity since Sunday, although power had since been restored in most areas.
Indonesia's geological agency said the quake on Thursday afternoon had a magnitude of 6.2 and was shallow, at a depth of 12 kilometres, centred in the north-west of the island.
Evacuees at a shelter in northern Lombok's Tanjung district ran out onto the road crying and screaming, an AFP reporter at the scene said.
Disaster agency spokesman Sutopo Purwo Nugroho said in a statement that information being provided by different agencies needs to be complete before it can be cross-checked and officially verified.
The footage of the prayer led by Imam Arafat at the Musholla As-Syuhada Mosque was being broadcast live on Facebook on Sunday night when a magnitude 7.0 natural disaster hit the neighboring Lombok Island.
A humanitarian crisis is also looming in Lombok, where thousands have been left homeless and in desperate need of clean water, food, medicine and shelter.
The Indonesian military said that three Hercules transporter planes packed with food, medication, blankets, tents and water tanks had arrived in Lombok.
Workers with heavy machinery are searching the rubble of homes, schools and mosques, with hope of finding any survivors fading.
A green and yellow dome rested on the pile of rubble, the only part of the structure still intact.
Indonesia is prone to earthquakes because it lies on the Ring of Fire - the line of frequent quakes and volcanic eruptions that circles virtually the entire Pacific rim.
Local authorities, global relief groups and the central government have begun organising aid, but shattered roads have slowed efforts to reach survivors in the mountainous north and east of Lombok, which bore the brunt of the quake.