CAIRO, Apr. 25 (Aswat Masriya) – Egypt's press syndicate said Monday that arrests and assaults on journalists have been on the rise during the past few hours as protests against the recent Egyptian-Saudi demarcation agreement were set to start.

The syndicate's operation room documented the detention of twelve journalists throughout the day and "assault" on three others. 

Four other journalists were held captive for a while before they were released, the syndicate said in its latest statement on Monday.

Security forces blocked the roads leading to the press syndicate and cordoned off the area early Monday ahead of planned protests that were called for by various political factions and groups in opposition to the sovereign transfer of two Red Sea islands, Tiran and Sanafir, to Saudi Arabia.

The maritime border demarcation agreement was announced by the cabinet on April 9 during King Salman's visit to Cairo, which witnessed the signing of several other agreements.

The press syndicate said in its statement that security forces used the help of "groups of thugs" in an attempt to storm the syndicate's headquarters. Meanwhile, several journalists were denied entry to the syndicate in what the syndicate described as a "crime against the syndicate and journalists."

It further called on the interior ministry to release journalists who were still detained.

Among reported violations, the BBC crew's car was stopped by the police in the vicinity of Tahrir Square and were prevented from shooting.

The agreement stirred controversy and prompted thousands of protesters to demonstrate in front of the press syndicate under the slogan "Friday of the Land" on Apr. 15.

Protesters ended the demonstration then but said they will resume protesting on Apr. 25.

Egypt's interior ministry tightened security measures on trains and buses and in metro stations on Sunday ahead of planned protests and threatened to respond with "utmost firmness" to any action that disturbs public security.