An Israeli air strike has hit the northern Gaza Strip and killed one Palestinian and wounded two others, emergency services have said.

The strike came on Wednesday after a rocket fired from the territory earlier in the day landed in southern Israel, causing no casualties.

The latest escalation came little more than a week after a Palestinian unity government was sworn in, replacing separate administrations in Gaza, run by Hamas, and in the West Bank run by loyalists of president Mahmoud Abbas.

Abbas' office condemned the rocket fire and urged Gaza armed groups to abide by previous ceasefire deals with Israel.

Israeli government spokesman Mark Regev dismissed the condemnation as "empty rhetoric," saying Abbas should instead keep earlier pledges to disarm Gaza's fighters.

The US, however, welcomed Abbas' words and suggested it was not ready to hold the new unity government responsible for the attack.

"We expect the Palestinian Authority will do everything in its power to prevent attacks from Gaza into Israel, but we acknowledge the reality that Hamas currently controls Gaza," US State Department spokeswoman Jen Psaki said.

Protests

Meanwhile, Palestinian protesters in the West Bank found a timely way to show support for dozens of Palestinian hunger strikers in Israeli jails. A day before the start of the World Cup in Brazil, they dressed up in the jerseys of the Palestinian football team and kicked a ball around outside Ofer, an Israeli lockup in the West Bank.

A group of helmeted soldiers prevented them from advancing. Troops fired stun grenades and pushed some of the protesters who dribbled and kicked the ball over the heads of soldiers.

Some of the Palestinian prisoners began their hunger strike on April 24, with others joining later, and more than 70 have been hospitalised.

The hunger strikes demand that Israel end the practice of administrative detention in which nearly 200 Palestinians are currently held without charges.