BETHLEHEM (Ma'an) -- The military wing of Islamic Jihad said it fired a Fajr rocket at Tel Aviv on Thursday, as warning sirens sounded in Israel's main city.
"We have widened the range of the battle to reach Tel Aviv and what is coming will be greater," the al-Quds brigades said in a statement.
Minutes earlier, sirens sounded in Tel Aviv and Israel's Army Radio reported a missile strike.
Air raid sirens sounded in Israel's commercial center during the evening rush hour, sending commuters scurrying from buses to seek shelter, and an explosion was heard.
Israel's chief military spokesman said no rocket had struck the city. A security source said it fell into the Mediterranean.
Defense Minister Ehud Barak said militants would be made to pay a price for firing rockets toward Tel Aviv.
"This escalation will exact a price that the other side will have to pay," Barak said in broadcast remarks after the rockets were fired.
He also announced he had ordered the military to enlist more reservists "so that we can prepare for any development". The Israeli armed forces chief spokesman said the military had the green light to call in up to 30,000 reserve troops.
Earlier Thursday, Israel's army said a projectile hit an open area near Rishon Lezion, a city 12 km south of Tel Aviv. The Israeli daily Haaretz said two rockets had landed, but no casualties were reported.
Israeli media reports said the rocket came down near an amusement park in sand dunes on the edge of the city.
Hamas' armed wing the al-Qassam Brigades said it had fired two rockets in the vicinity of Tel Aviv.Declaration of war
Militant groups in Gaza vowed on Wednesday to respond to Israel's assassination of a top Hamas military commander.
Islamic Jihad said the assassination of Ahmad al-Jaabari was a declaration of war. "Israel has declared war on Gaza and they will bear the responsibility for the consequences," the movement said.
A spokesman for Islamic Jihad's military wing said fighters had received orders to "respond fiercely" to the killing of al-Jaabari. All militant factions in the Gaza Strip are on a state of alert and will retaliate "in hours," Abu Ahmad said.
Israel has killed 15 Palestinians in the Gaza Strip since Wednesday in a series of air raids, naval attacks and tank shelling. Palestinian fighters have fired hundreds of rockets at Israeli military sites and across the border, killing three Israelis on Thursday morning.Reuters contributed to this report.