An Israeli military court ordered a Palestinian journalist to be detained for four months without trial or any charges Monday, on the eve of World Press Freedom Day.

Omar Nazzal was arrested on April 23 at the border between the Israeli-occupied West Bank and Jordan, where he had been due to fly to a European Federation of Journalists gathering in Bosnia.

The military court met on Sunday before announcing its decision to put him in administrative detention for four months, said Wafa, the official Palestinian news agency.

An Israeli army spokeswoman confirmed Nazzal would be held in administrative detention until August 22 "over his participation in a terrorist organisation" and not "because of his activity as a journalist".

Under its administrative detention law, Israel can hold suspects for indefinite periods without charging or putting them on trial.

Israel's Shin Bet security service said Nazzal, a member of the general secretariat of the Palestinian Journalists Syndicate (PJS), was detained because of "his involvement in terror group activities".

It said the journalist, 54, was recently appointed to a top position at Falestine al-Youm television which Israel's army forcibly closed in Ramallah on accusations of incitement to violence.

Nazzal left the position several months ago.

Monday's court announcement comes on the eve of World Press Freedom Day, the lead-up to which Palestinians have been using to condemn Israel.

Hanan Ashrawi, a Palestinian political leader, on Monday urged immediate intervention "to ensure Israel is accountable for the blatant and planned escalation against Palestinian media".

The journalists' union says that Israel is also holding in detention another 19 Palestinian journalists and students of journalism, one of them for more than 20 years.

Israel has also forced the closure of several Palestinian television and radio stations since the outbreak of a wave of attacks that has killed more than 200 Palestinians and about 30 Israelis since October.