Analysts differ over responsibility but agree that attack was aimed at reconciliation efforts
Abdel Satter Qassem
Palestinians fear severing of Qatari lifeline to isolated territory.
Assassination of Mazen al-Fuqaha seen as challenge to new Hamas leader.
Kifah Quzmar is one of many Palestinians to be arrested for writing on Facebook.
Abdel Sattar Qassem is an outspoken critic of security coordination with Israel.