Separately on Tuesday, Israel's army said dozens of mortar shells were launched toward Israel from the Gaza Strip, with most intercepted by the country's air defence system
Israeli forces stopped and seized a Palestinian protest boat on Tuesday, the army said, as those aboard sought to demonstrate against the Jewish state's blockade of Gaza.
The incident occurred amid high tensions in the Gaza Strip after militants fired some 28 mortars in the direction of Israel, whose military retaliated by hitting dozens of targets.
The boat, carrying sick Gazans and those unable to find work, was stopped by Israeli forces several miles out at sea.
"The Israeli Navy apprehended a Palestinian boat with approximately 17 Palestinians that attempted to breach the legal naval blockade," the army said in a statement, saying the incident took place "without exceptional events."
The boat will be searched and taken to the Israeli port of Ashdod, it added.
Those on board will be questioned and then returned to Gaza, the army added.
Protest spokesman Adham abu Salmiya estimated the boat was several miles beyond the nautical blockade imposed on Gaza when it was intercepted.
"This is the first Palestinian ship to reach this distance since the Oslo Accords," he said.
Under the Oslo Accords of the early 1990s, fishermen are supposed to be allowed to fish up to 20 nautical miles off the coast.
But Israel has restricted that to a maximum of 14.5km in recent years, citing the threat of Gaza's Islamist rules Hamas.
Organizers said they were seeking to highlight the impact of the blockade on Gaza's two million residents.
In 2010, Israeli commandos killed nine Turkish activists when they raided a six-ship flotilla trying to reach the Gaza Strip in defiance of the blockade. Another activist died years later.
The botched raid angered Turkey and saw it cut off ties with Israel until 2016.
Separately on Tuesday, Israel's army said dozens of mortar shells were launched toward Israel from the Gaza Strip, with most intercepted by the country's air defence system.
Israeli officials said it was the largest such barrage from Gaza targeting Israel since the 2014 war.
Israeli Prime Minister Benjamin Netanyahu pledged to respond "powerfully" to the mortar fire and the army struck more than 30 "military targets" in the Gaza Strip on Tuesday afternoon.
The Gaza Strip has been under Israeli blockade for more than a decade, with Israel saying it is necessary to prevent Hamas from obtaining means to attack.
The boat protest comes after weeks of deadly demonstrations and clashes along the Gaza-Israel border, beginning on March 30.
Protesters have called for Palestinians who fled or were expelled in the 1948 war surrounding Israel's creation to be allowed to return to their former homes now inside Israel.
The demonstrations peaked on May 14, when at least 61 Palestinians were killed as tens of thousands of Gazans protested and clashes erupted on the same day the US moved its embassy in Israel from Tel Aviv to Jerusalem.
Protests and clashes have continued at a low level since then. At least 121 Palestinians have been killed by Israeli fire in the unrest.