By Nidal al-Mughrabi CAIRO, June 6 (Reuters) - An Israeli strike killed at least seven Palestinians including two women in Gaza on Saturday, health officials said, as mediators restarted talks in Cairo with Hamas and other factions over safeguarding a strained ceasefire agreement. Medics said seven people were killed and 15 others, including children, were wounded when an Israeli airstrike targeted a large tent encampment in the heart of Gaza City.