"Spain's voice will always be raised to protect the rights of the Palestinian civilian population in Gaza," Albares said on a visit to Morocco.
"We must make a distinction between terrorist targets and the civilian population. We cannot have places of worship, hospitals, United Nations offices as targets," he said at a joint press conference with his Moroccan counterpart Nasser Bourita.
Albares said Spain had condemned the attacks launched by Hamas on Israel on October 7 and that Israel had the right to defend itself, but "this defence against this terrorist attack must be done within the limits of international humanitarian law".
Some 1,200 Israelis, most of them civilians, were killed in the attacks, in which Hamas gunmen also took some 240 hostages, according to Israeli officials.
In response, Israel launched an unrelenting military offensive that has left swathes of Gaza in ruins. The health ministry in the Hamas-run territory said 18,787 people have been killed, mostly women and children.
Albares said the population of Gaza "must be guaranteed the most essential supplies: water, food, medicine, fuel".
He renewed Spain's call for an international peace conference, which he said should lead to the creation of a "realistic and viable" Palestinian state "with Gaza and the West Bank connected and its capital in east Jerusalem".
His Moroccan counterpart called upon the international community "to assume its responsibility to start a real political process that leads to a two-state solution".
Among European Union member states, Spain has been one of the most critical of Israel's conduct of its war with Hamas.
Last month, Israel recalled its ambassador from Madrid in protest at comments made by Spain's Prime Minister Pedro Sanchez expressing "serious doubts" about the legality of Israel's military campaign.
In recent weeks, other Western governments have stepped up their criticism of Israel's failure to reduce the civilian death toll in Gaza.
On Tuesday, US President Joe Biden warned Israel's "indiscriminate bombing" of Gaza was eroding international support.
But on Wednesday, Israeli Foreign Minister Eli Cohen retorted that the war in Gaza would continue "with or without international support".
