Over 2,300 Palestinian security prisoners refused food on Tuesday to mark Palestinian Prisoners Day, and 1,200 of these launched a full-fledged hunger strike.

Eight pro-Palestinian ‘flytilla’ activists who were refused entry into Israel also refused food in solidarity with the Palestinian prisoners.

The hunger-striking detainees, some 30 percent of the 4,600 Palestinians in Israeli jails, launched the open-ended strike to protest prison conditions, as well as the policy of administrative detention, which sees them held without being charged.

Tuesday also marks the release of prisoner Khader Adnan, who made world headlines after refusing food and drink for 66 days to protest his detention without charge earlier this year.

Adnan, a baker and Islamic Jihad member, agreed to begin eating again once Israel promised to release him.

Hana Shalabi, who was re-arrested in February after being freed as part of the Gilad Shalit prisoner exchange, struck a deal in late March to be deported to Gaza for three years in exchange for ending her 43-day hunger strike.

Before Tuesday’s mass action, there were eight detainees on hunger strike in Israeli jails, seven of them in administrative detention.

Hamas and Islamic Jihad prisoners are striking collectively, by decree, and they were joined by individual Fatah and PFLP members, according to a Physicians for Human Rights official.