Anyone can get a Grad rocket!

An interesting item from Ma'an:

A group calling itself the Marwan Haddad division of the Abdullah Azzam Brigades, a new Palestinian military group in Gaza, said its fighters had launched a homemade projectile toward Israel late Sunday night.

"Israel is not safe from the resistance," a statement from the group said, adding that the projectile was aimed at the Ashkelon power plant.

The group said it would not accept truce conditions with Israel, and announced the launch less than an hour before a ceasefire deal was set.

On Sunday morning, the group issued its first statement, saying fighters had fired a Grad-style missile at the Israeli city of Ashkelon and two homemade projectiles at the Zikim military base.

A little-known group in Gaza can get their hands on a Grad rocket?

This means that either this tiny group is:

1.  Lying.
2.  In contact with arms dealers from Egypt and likely Sudan in order to smuggle Grad rockets through the Rafah tunnels.
3. Purchasing or stealing extra Grads from Hamas or Islamic Jihad.
4. Working with existing terror groups in Gaza like Hamas to be able to shoot rockets into Israel while giving the larger groups plausible deniability when they announce "cease fires."

I would guess the chances of each are 20%, 0%, 20% and 60%, respectively.