The rockets are being launched mainly due to rivalries within Gaza, by small Salafi organizations that want to embarrass Hamas and bring about an escalation. These groups can’t fire rockets in large quantities, but can nevertheless fire enough to pose a challenge to Hamas.
Defense officials believe Hamas is already at the limits of its ability to influence these organizations. Both Israel and Hamas fear that the latter’s influence might wane, leading it to lose control, which in turn would lead to an escalation with Israel.