Palestinian militants resumed rocket attacks on Tel Aviv on Monday after a 24-hour lull in strikes on the Israeli commercial capital, and Israel kept up its air and naval bombardments of the Gaza Strip despite growing pressure for a ceasefire.

The military said it had shot down a drone from Gaza, the first reported deployment of an unmanned aircraft by Palestinian militants whose rocket attacks have been regularly intercepted.

The use of a drone would mark a step up in the sophistication of the Palestinian arsenal, although it was not immediately clear whether it was armed.

Around half a dozen Israelis have been wounded since the start of the week-old offensive, which Gaza health officials say has killed 169 Palestinians, most of them civilians.

International calls for a ceasefire have grown as the death toll has mounted in the worst flare-up of Israeli-Palestinian violence for almost two years, sparked by the murder of three Israeli teenagers and revenge killing of a Palestinian youth.

Israel has arrested three people, two of them minors, over the Palestinian's murder and officials said on Monday they had confessed to burning him alive.

The European Union said on Monday it was in touch with "all parties in the region" to press for an immediate halt to the hostilities, a day after U.S. Secretary of State John Kerry offered to help secure a Gaza truce.

Egypt and Qatar were also involved but peace efforts were complicated by Hamas's rejection of a mere "calm for calm" in which both sides hold their fire in favour of wider conditions including prisoner release and an end to Israel's Gaza blockade.

The Israeli army said its aircraft and naval gunboats attacked dozens of targets in the Gaza Strip and that Palestinian militants fired more than 20 rockets into Israel, slightly wounding a boy in the town of Ashdod, where a home was damaged. Palestinian health officials said at least 20 people in Gaza were wounded.

But Israel did not carry out a threat to step up attacks against rocket-launching sites it said were hidden among civilian homes in the town of Beit Lahuiya after urging residents there to leave. A U.N. aid agency said around a quarter of the town's 70,000 residents had fled.

Tel Aviv experienced a rare lull in morning rocket strikes, but they resumed during the evening rush hour, with the Iron Dome missile interceptor system going into action. There were no reports of casualties or damage.

 

"SPECIAL MISSIONS"

Hamas, the Islamist group which runs Gaza, said its armed wing had sent several locally-made drones to carry out "special missions" deep inside Israel.

A military spokesman said the drone was intercepted near the port of Ashdod by a U.S.-built Patriot missile, used largely ineffectively by Israel against Iraqi Scud missiles in the 1991 Gulf War.

The force was trying to locate debris in the area about 25 km (15 miles) north of Gaza, and determine whether it had carried explosives.

"Hamas is trying for an achievement at any price," Israeli Defence Minister Moshe Yaalon, referring to the drone, said in a statement. "We will continue to pummel Hamas and other terrorist organisations until the safety of Israeli citizens is ensured."

An Egyptian-brokered truce doused the last big Gaza flare-up in 2012, and U.N. Secretary General Ban Ki-moon told Egyptian President Abel Fattah al-Sisi in a phone call that his country is the most credible party capable of persuading both sides to stand down, an official Egyptian statement said.

But Cairo's government is at odds with Islamist Hamas, complicating a mediation bid with the group, an offshoot of the now-outlawed Egyptian Muslim Brotherhood.

Asked if Egypt was mediating, Foreign Ministry spokesman Badr Abdelatty said only that Cairo was "in close contact with the Israelis and all Palestinian factions as well as with regional and international countries".