Under the Moroccan constitution, a letter signed by the monarch has the authority of a royal decree and the monarch has the power to distribute jobs, both military and civil.
Some members of the so-called National Autonomous Group of Holders of Royal Letters have waited 10 years for a promised job, they said.
Members of the Rabat-based group, which has twice before attempted suicide, had said they planned to kill themselves on 17 March if jobs did not materialise.
Authorities intervened and arrested seven members of the group, accusing them of trying to burn down public offices in the capital. The group claims eight of its members were arrested.
"We found 17 litres of fuel and several Molotov cocktails with them. They wanted to set ministries nearby on fire," an Interior Ministry official, who declined to be named, told Reuters on Thursday.
The National Autonomous Group criticised authorities for heavy-handed tactics in breaking up the sit-in.
"Police beat up members of the group, leaving several injured," the group said in a statement.
Royal recruitment letters have already changed the lives of some 3000 Moroccans, mainly jobless graduates, disabled, poor and inhabitants of the disputed Western Sahara territory.