GAZAinfo-icon:- Israelinfo-icon launched air strikes on Gaza hours after rockets were fired near Tel Aviv, raising fears of a major escalation in the Israeli-Palestinian conflictinfo-icon. 

Explosions were heard in the Gaza Strip early Friday and Palestinian witnesses said Israeli planes bombed Hamas security positions.

There was no immediate word of casualties. About 30 strikes targeted positions held by the military wing of Hamas and their ally Islamic Jihadinfo-icon, causing significant damage, a Gazan security source told AFP news agency.

The Israeli military said it was attacking "terror sites" in Gaza, hours after it said two rockets were launched from the enclave at the Tel Aviv area.

The air attacks were taking place in the southern Gaza town of Khan Younis, about 25km south of Gaza City.

The rocket fire on Tel Aviv, the first since 2014, marks a significant escalation that raised the likelihood of a harsh Israeli reprisal.

The rockets triggered air raid sirens across the city - about 80km north of Gaza - which is Israel's densely populated commercial and cultural capital.

Explosions were heard in Tel Aviv and witnesses said Iron Dome interceptor missiles were fired skyward and detonated - although the military said no rockets were shot down.

"I heard the rocket and I heard the siren going off. It was a bit surprising, I didn't think that, you know, it could really reach Tel Aviv," said resident Yonah Zeff.

Naftali Bennett, Israeli's security minister, accused Hamas of responsibility.

"It's time to defeat Hamas. It's time to act unilaterally and demilitarise Hamas in order to defend Israeli citizens," said Bennett.

Warplanes could be heard flying overhead in Gaza City, where smoke from the explosions could be seen in the distance.

Vow to take action

Hamas denied responsibility for the attack on Tel Aviv, saying the rockets were launched when the group's military wing was meeting with Egyptian mediators to try to strengthen a ceasefire with Israel.

In an unusual step that indicated Hamas was attempting to prevent further escalation, the interior ministry said the rocket fire went "against the national consensus" and promised to take action against the perpetrators.

Islamic Jihad and the Popular Resistance Committees, two smaller Gaza armed factions, also denied responsibility.

Brigadier-General Ronen Manelis, the Israeli armyinfo-icon's chief spokesman, said officials had no prior warning of the attack and were trying to determine who fired the rockets.

Israel holds Gaza's Hamas rulers responsible for all fire out of the territory.

The rocket salvo caused no damage or casualties, but it rattled Israeli nerves ahead of an April 9 election in which Prime Minister Benjamin Netanyahu is seeking a fifth term on the strength of his national security and diplomatic credentials.

Netanyahu rushed to the military headquarters in Tel Aviv and was conferring with senior army officials.