An Israeli missile fired from a helicopter gunship killed two Palestinian farmers near the northern Gaza border with Israel Thursday, a Palestinian health official said dpa reported
The two were killed as Palestinian militants engaged in a gunfight with an Israeli engineering force on the Israeli side of the border.
The gunbattle came after about 40 hours of relative calm.
The sides had tried to observe an Egyptian-mediated informal truce after an escalation in Palestinian rocket fire and Israeli retaliatory airstrikes over the last days.
Gaza emergency services chief Adham Abu Salmeya said ambulances were taking two bodies to hospital.
They were said to be civilians, while the militants involved in the gunbattle escaped.
An Israeli military spokeswoman in Tel Aviv said the engineering force had been carrying out "routine" work at the security fence separating Israel from northern Gaza when it came under fire.
Local residents said Israel responded by firing about two tank shells and one or two missiles from a helicopter gunship.