The Israel Defense Forces said the teens were attempting to plant explosives near the border in an attempt to breach the fence.
There have also reportedly been talks with a view to Israel allowing Qatari cash into the Gaza Strip to pay public salaries.
The boys' bodies were wrapped in Palestinian flags and carried by mourners who shot in the air as they chanted "God is Great".
U.N. Secretary-General Antonio Guterres "deplores" the deaths of the three Palestinian children, a spokesman said.
The incident occurred with tensions high along the border after months of protests and clashes.
"It's normal for them to go there, and that's why we did not expect them to be martyred", said Salwa Abu Isied, Khaled's mother. "The small blaze that was under the auto sparked a fire in a pipe in the fuel system, which caused the fire to spread to the front part of the auto and caused significant damage to the vehicle", he said.
Israel's army said Tuesday it has opened a military police investigation into the killing of a Palestinian medical volunteer along the Gaza border in June.
Govt Sends Letters to RBI Invoking Section 7 of RBI Act
Arguing against the Centre's proposal, the RBI had said, "The digital payments have made good and steady progress". Essentially, they want to ease non-performing asset norms and relax lending norms for MSME companies.
He added that there was no reason to take entering a restricted area along the border, or even planting explosives there, should be taken as threatening and "doesn't mean someone's life is at imminent threat".
The Israelis have launched three wars since 2008 against Palestinians in the Gaza enclave and the ruling resistance group there, Hamas.
Thousands gathered Monday on the beach for a Hamas-led protest against the blockade.
Some 80 Palestinian protesters were injured, on Monday, during the 14th naval march at the northern borders of the besieged Gaza Strip.
"Israel's continuous campaign of excessive and indiscriminate violence against the people of Gaza has persisted with impunity and has been emboldened by the U.S. administration's strategic alliance with Israel", she added.
Israel says its actions are necessary to defend the border and stop infiltrations and attacks, which it accuses Hamas of seeking to orchestrate.
Protesters demand the right to return to their homes and villages in historical Palestine, from which they were driven in 1948 to make way for the new state of Israel.