Abdullah Salem Al Sabah

One of the emir's great-nephews is sympathetic to the Kuwaiti opposition:

Kuwait has released Shaikh Abdullah Salem Al Sabah, one of two members of the ruling family arrested for tweets deemed critical of the government, he said on Twitter on Saturday...

Shaikh Abdullah said he was questioned by the secret service police on accusations of insulting Emir Shaikh Sabah Al Ahmad Al Sabah and instigating against the regime.

He is the grandson of the emir’s half-brother, the late Shaikh Abdullah Al Ahmad Al Sabah.

The two young royals have written tweets sympathetic to the Kuwaiti opposition, which has been organising protests against an amendment to the electoral law seen as a ploy to produce a pro-government parliament in a snap December 1 general election.

I have no background on the other detained prince, one Nawaf Malik al-Sabah.