Which docs needed for minor if one parent i is missing

[chanap]

Hi,

I am a single mother of 2 kids (14 and 7 yr daughters). I already have US Visa B2 and visited USA 2 years back for 1 month to my brother's place.

I am neither divorsed nor widow. But 5 yrs back (2014)my husband gone missing (went for meeting and never came back) FIR for missing was recorded and we whole family tried hard searching him but no success.

Later in 2017 i got Passport of both my kids with lot of paper work and so many visits to passport office for many months.

Now i want my kids to visit USA at their Mamu's (my brother) place.

But read that both parent's consent is required for minor's Visa.

In case of single parent, where mother is neither divorser nor widow and father is not available for consent (missing) what all documents are needed to get Kids Visa done.

Any body please help.

Thanks and Regards
Chanap