Cannot use 'new' with the Function type in TypeScript

I have this code:

const BlockConstructors: Function[] = [
 OBlock,
 IBlock,
 TBlock
];

function randomFromArray(array: any[]) {
  return array[Math.floor( Math.random() * array.length )];
}

const BlockConstructor: Function = random(BlockConstructors);
const block: Block = new BlockConstructor();

I try to draw a some block constructor from array and then create a new object, all my block constructors in array extends Block class. I get error:

Cannot use 'new' with an expression whose type lacks a call or construct signature.

Why this error appears?