What is the ruling on building graves out of cement, raising them above the ground, and burying more than one deceased person in a single grave?

The questioner : Now, what is the ruling on graves that are built with cement and raised above the ground, O Shaykh, given that there is no space, and more than one deceased person is placed in them?

The Shaykh : I am unable to issue a ruling on this because it does not exist in our country.

The questioner : Yes, Shaykh.

The Shaykh : It only exists in other countries, and the people of those countries must resolve the issue.