A Gaza farmer was killed and a second man was wounded by an Israeli tank shell on Friday, a Gaza health ministry spokesman said, on a day of heightened tensions ahead of planned protests by Palestinians along the border with Israel.

The Israeli military declined initial comment and was checking for details.

The Gaza health ministry spokesman said the farmer was killed and another wounded near the town of Khan Younis. Residents there said he was gathering crops to sell later.

"Omar Samour, 27, was martyred and another citizen was wounded as a result of (Israeli) targeting of farmers east of Qarara village," the health ministry said.

More than 100 sharpshooters had been deployed on the Gaza border ahead of the planned mass demonstration

Palestinians in the Gaza Strip are planning to begin a six-week-long tent city protest to demand Palestinian refugees be allowed to return to what is now Israel.

Israeli security forces are on heightened alert. Israel's military chief said in an interview on Wednesday more than 100 sharpshooters had been deployed on the Gaza border ahead of the planned mass demonstration near the frontier.

Organisers from a number of factions, including Islamist Hamas, which dominates Gaza, hope thousands will answer their call to flock to tent cities in five locations along the sensitive border to call for a right of return of Palestinian refugees to what is now Israel.

The Israeli military, citing security concerns, enforces a "no go" zone for Palestinians on land in Gaza adjacent to Israel's border fence.

The March 30 date for the start of the protest marks "Land Day" commemorating the six Arab citizens of Israel who were killed by Israeli security forces during demonstrations in 1976 over government land confiscations in northern Israel.

It is due to end on May 15, the day Palestinians call the "Nakba" or "catastrophe", marking the displacement of hundreds of thousands of Palestinians in the conflict surrounding the creation of Israel in 1948.