JERUSALEM -- Iran fired a fresh barrage of missiles towards northern Israel on Thursday afternoon, the Israeli military said, as hostilities between the two countries entered their sixth day.

The Israel Defense Forces (IDF) said between 10 and 15 missiles were launched, according to Israeli media reports. Air raid sirens sounded across northern Israel, including Haifa, the Galilee region and the Sea of Galilee, forcing hundreds of thousands of residents to seek shelter.

There were no immediate reports of direct hits or major casualties. Israel's national emergency service, Magen David Adom, said one woman sustained minor bruises while on her way to a shelter.

Earlier on Thursday, an earlier missile barrage from Iran targeted central Israel, including the Tel Aviv metropolitan area, and struck a building at Soroka Medical Center in southern Israel. Authorities said 271 people were injured in that attack, four of them seriously and 16 moderately.

Israeli army radio reported that at least one of the missiles fired at Tel Aviv contained multiple sub-munitions, which dispersed across various locations upon detonation. The army's Home Front Command said each sub-munition had an explosive yield similar to that of short-range rockets typically used by Hezbollah in Lebanon. While the affected area was wider, the explosive power of each sub-munition was significantly lower than that of standard ballistic warheads, it added. Authorities warned residents to avoid handling any debris or unexploded ordnance.

The escalation follows Israeli airstrikes on targets inside Iran on June 13, which triggered the current exchange of attacks. Official figures indicate nearly 600 people have been killed in Iran and 24 in Israel since the conflict began.