JERUSALEM (JTA) — Classes at schools not fortified against rockets located in the southern Israel municipality of Ashdod were cancelled over fears of rocket attacks from Gaza.

Some 4,000 students stayed home Monday; there are about 54,000 schoolchildren in Ashdod.

Classes were cancelled after the Israeli military on Sunday in a targeted attack critically injured an Islamic Jihad operative who the Israel Defense Forces said is an expert in rocket launching and was directly responsible for five rockets fired last week at Ashkelon, that were intercepted by the Iron Dome missile defense system.

Municipal officials feared retaliatory attacks.

An Iron Dome battery was moved to Ashdod early Monday morning, according to reports.