Israel's military has struck numerous targets in the Gaza Strip after Benjamin Netanyahu, the Israeli prime minister, said his country needed to be prepared for a long conflict in the Palestinian territory.

By daybreak on Tuesday, a cloud of thick dust from the explosions hung over Gaza City after Israeli forces fired hundreds of flares that turned the night sky bright orange.

At least 30 people were killed in the Israeli assaults from air, land, and sea, residents said, in the most widespread night of attacks so far. At least 1,110 Palestinians, most of them civilians, have died in the ongoing Israeli offensive.

Eleven people were killed in a strike on a house in the Bureij refugee camp in Gaza City as Israeli forces hit targets across the coastal strip, including a government complex.

Israeli aircraft also fired a missile at the house of Ismail Haniyeh, Gaza's senior Hamas leader, before dawn on Tuesday, causing damage but no casualties, Gaza's interior ministry said.

The Gaza Strip's sole power plant was on fire on Tuesday morning after being struck by at least one artillery shell, Palestinian news agencies said.

Fathi Khalil, deputy head of Gaza's energy authority, said flames caused by an artillery shell spread to fuel tanks. Large pillars of black smoke could be seen rising from the complex.

Children killed

The overnight strikes came after a day of heavy Hamas-Israeli fighting in which nine children were killed by a strike on a Gaza park where they were playing, according to Palestinian health officials - a tragedy that each side blamed on the other.

The Hamas-run Health Ministry said 10 people, including nine children under the age of 12, were killed and 46 wounded in the blast at a park in the Shati refugee camp on the outskirts of Gaza City.

The Israeli military said five soldiers had died in a gun battle with fighters who crossed into Israel via a tunnel near the community of Nahal Oz, close to the border with the Gaza Strip.

Hamas said its forces had infiltrated Israel to retaliate for the killing of children in a beach camp.

The incident on Monday raised to 10 the number of military fatalities for the day.

Fifty-three Israeli soldiers have been killed since Israel launched its offensive on Gaza.

Hamas said that its broadcast outlets, Al Aqsa TV and Al Aqsa Radio, were also targeted. The television station continued to broadcast, but the radio station went silent.

In a televised address on Monday night, Netanyahu said any solution to the crisis would require the demilitarisation of the Palestinian territory, controlled by Hamas and its allies.

"We will not finish the mission, we will not finish the operation without neutralising the tunnels, which have the sole purpose of destroying our citizens, killing our children," Netanyahu said, adding that it had been a "painful day".

"We need to be prepared for a protracted campaign. We will continue to act with force and discretion until our mission is accomplished," Netanyahu said.

As he spoke, the Israeli military sent messages to thousands of Palestinians in Shujayea, Zeitun, Jabaliya, Beit Lahiya, and Beit Hanun, urging them to flee their homes and seek shelter in central Gaza City.

Wave of air strikes

The main UN agency in Gaza, UNRWA, said on Monday more than 167,000 displaced Palestinians had taken shelter in its schools and buildings, following the Israeli evacuation warnings.

Shortly afterwards, the cloudy skies over Gaza lit up with flashes as the army began an intensive wave of air strikes and heavy shelling, AFP correspondents and medics said.

As night fell, army flares illuminated the sky and the sound of intense shelling was heard.

A number of rockets fired from Gaza were launched towards southern and central Israel, including the Tel Aviv area.

At least one rocket was intercepted by the Iron Dome system. No casualties or damage were reported.

Israeli tanks also shelled border areas of Gaza, killing five people, including three children and a 70-year-old woman, and wounding 50 in the town of Jabaliya, which was among the areas warned to evacuate, the Red Crescent said.

The explosion of violence, after a day of relative calm, ended international hopes of turning a brief lull into a longer-term ceasefire.

Hamas said it had accepted a UN call for a pause in hostilities on Monday to coincide with Eid al-Fitr, which marks the end of the fasting month of Ramadan.

Israel initially hesitated, having abandoned its own offer to extend a 12-hour truce from Saturday when rockets kept flying from Gaza.

An opinion poll broadcast by Israel's Channel 10 television showed overwhelming public support for continuing the Gaza offensive until Hamas is "disarmed".

However, foreign pressure has been building on Netanyahu to rein in his forces.

Both US President Barack Obama and the UN Security Council called for an immediate ceasefire to allow relief to reach Gaza's 1.8 million Palestinians, followed by negotiations on a more durable cessation of hostilities.

Israel wants guarantees Hamas will be stripped of its tunnels and rocket stocks.

In his television address on Monday night, Netanyahu said any solution to the crisis would need to see Hamas stripped of its weapons.

"The process of preventing the armament of the terror organisation and demilitarisation of the Gaza Strip must be part of any solution. And the international community must demand this forcefully," he said.

Sami Abu Zuhri, Hamas spokesman, said: "[Netanyahu's] threats do not frighten either Hamas or the Palestinian people, and the [Israeli] occupation will pay the price for its massacres against children and civilians."

Israel launched its offensive on July 8 with the aim of halting rocket attacks by Hamas and its allies.