GAZA/JERUSALEM - Gaza militants fired dozens of rockets into Israel on Saturday, drawing a wave of Israeli air strikes that killed a Palestinian baby and a gunman, as hostilities flared across the border for a second day.

The escalation began on Friday when a sniper from the Palestinian Islamic Jihad militant group fired at Israeli troops across the border wounding two of them, according to the Israeli military. A retaliatory Israeli air strike then killed two militants from the Islamist Hamas group that rules Gaza.

Two other Palestinians protesting near the frontier were also killed by Israeli forces.

On Saturday, Hamas and Islamic Jihad fired more than 200 rockets toward Israeli cities and villages. In response, the Israeli military said its tanks and aircraft carried out attacks against more than 30 militant targets belonging to both groups.

Explosions in Gaza City, where busy streets were packed with shoppers making preparations for the holy Muslim month of Ramadan, shook buildings and sent people fleeing for cover.

The Gaza Health Ministry said a 14-month old baby was killed by one of the Israeli strikes and at least 13 other Palestinians were wounded throughout Saturday. Residents identified two of them as militants.

"The Israeli plane fired a missile near the house and the shrapnel entered the house and hit the poor baby," said her aunt, Ibtessam Abu Arar. An Israeli military spokeswoman made no immediate comment.

A small armed pro-Hamas group in Gaza, The Protectors of Al-Aqsa, said one of its men was killed in another air strike.

Across the border, sirens sent Israelis running to shelters as the blasts of rocket interceptions sounded overhead. The Magen David Adom ambulance service said two people were wounded by shrapnel.

Israeli military spokesman Lieutenant-Colonel Jonathan Conricus said Israel was prepared to intensify its attacks. He added that Islamic Jihad was trying to destabilize the border and blamed Hamas for failing to rein it in.

In a joint statement in which they claimed responsibility for firing rockets, Hamas and Islamic Jihad said: "Our response will be broader and more painful if the enemy pursues its aggression."

Reuters