Human Rights Watch has implored the Israeli military to end the illegal shooting of Palestinian civilians near the Gaza border.

Israeli forces killed at least four Palestinian civilians and wounded other 60 since the beginning of this year, said HRW.

The victims included a disabled woman and a 16-year-old student who was reportedly shot dead as he was having a picnic with high school friends.

"Month after month, Israeli forces have wounded and killed unarmed Palestinians who did nothing but cross an invisible, shifting line that Israel has drawn inside Gaza's perimeter," said Sarah Leah Whitson, Middle East director at HRW.

"It's appalling that soldiers have shot men, women, and children apparently for simply crossing a line."

HRW accused Israel of breaching international human rights laws, which say lethal force can be used only to prevent an imminent threat to life.

"Soldiers do not face an imminent lethal threat from unarmed Palestinian civilians in areas of Gaza near the perimeter fence," HRW said. "Military personnel who wilfully kill civilians are committing a war crime."

Palestinians cannot be closer than 300 metres from the Gaza border fence, but they have been frequently shot even when they were beyond that distance, HRW said.

A spokesperson for the Israeli military said its troops are instructed to first fire warning shots when Gaza residents approach the perimeter.

If the targets fail to heed they are then shot in the legs before being eventually killed. The practice has been confirmed by Palestinian witnesses.

"Shooting at civilians is not a lawful policy near Gaza's perimeter fence or anywhere else," Whitson said. "Israeli commanders need to change their policies and practices to abide by international law, not flout it."

From 2005 until 2013, the Gaza-based Palestinian Centre for Human Rights (PCHR) submitted several complaints to the Israeli military asking officials to conduct criminal investigations into alleged killings and injuries in areas near Gaza's land perimeter.

The military has not opened any criminal investigations into their complaints, PCHR reported.

"Responses received from the [military] stated that the cases were closed because the victim had violated the access restrictions, or because the use of lethal force by the Israeli military was within its rules of engagement," the UN Office of the High Commissioner for Human Rights said.