An Israeli civilian died on Tuesday after being shot, apparently by a Palestinian sniper, as he was carrying out maintenance work along the border fence that separates Israel from the Gaza Strip.

Israeli Prime Minister Benjamin Netanyahu, who was visiting the southern town of Sderot, around a kilometer (0.6 miles) from the border with the Gaza Strip, vowed swift retaliation.

"This is a very severe incident and we will not let it go unanswered," Netanyahu said. "Our policy until now has been to act beforehand and to respond in force, and this is how we will act regarding this incident as well."

Israeli forces later launched a series of air strikes on the Gaza Strip. News agencies cited witnesses and officials from the Islamist organization Hamas, which rules Gaza, who said a young girl had been killed in one of the Israeli strikes, which targeted two of the group's training camps.

Hospital officials said a Palestinian had also been killed in a separate incident in northern Gaza earlier in the day.

Upsurge in incidents

These were just the latest in a series of incidents of violence in recent days.

On Sunday, a pipe bomb placed upon an Israeli bus - allegedly by Palestinian militants - went off but caused no casualties as it had been evacuated in time. On Monday, an Israeli policeman was wounded in a stabbing incident outside of a settlement in the West Bank, just hours after a rocket fired from Gaza landed in southern Israel.

This has been the biggest upsurge in violence since Israel and Hamas reached a ceasefire that ended eight days of heavy fighting in November 2012.

pfd/ph (Reuters, AP, dpa)