Israeli warplanes fired two missiles at a security compound in the Hamas-ruled Gaza Strip on Wednesday, killing two Palestinian militants, Hamas and Palestinian medical officials said.

The Israeli military confirmed it had struck a militant target in the coastal territory in response to a rocket fired at Israel earlier, which caused no casualties.

Hamas officials and medics said both men killed were security guards at the compound. Hamas's armed wing said both were members of it.

The strike was carried out a day after Israeli commandos seized a cargo ship in the Mediterranean carrying what Israel said were Iranian-supplied arms destined for Gaza.

An Israeli military official said 60 rockets and mortars have been fired at Israel from Gaza this year.