"People in Gaza are waiting in lines for almost everything, and that's if they're lucky enough to find something to wait for," says Bassam Nasser, 39.

An aid worker in Gaza City, he, like so many others there, including the UN relief agency, says living conditions are the worst he has ever seen in the strip.

"People queue for two or three hours for bread, but sometimes there's no cooking gas or flour, so no bread.

"People wait in line for UN food handouts, but sometimes there aren't any. The suffering is reaching every aspect of life."

As well as working for an American development agency, Mr Nasser is a Gazan, and a father.

"I've got three young children. It's difficult to explain to them that it's not my fault we don't have electricity and that it's not in my control."

'Severely stretched'

Since June 2007, Israel has allowed little more than basic humanitarian aid to enter the Gaza Strip.

Many there hoped that policy would change, five months ago, when Hamas and Israel agreed to a truce.

But while there were some increases in the amount of aid allowed in, Israel's strict restrictions on the movement of goods and people into and out of Gaza largely remained.

Two weeks ago, an already fragile humanitarian situation resulting from the mounting effects of months of shortages, saw a dramatic downturn.

The fighting resumed, with an Israeli army incursion into Gaza and a retaliatory barrage of militant rocket fire. With that, Israel all-but shut the Gaza Strip.

Although there are some goods being smuggled into Gaza through tunnels from Egypt, little else is reaching the territory.

Serious fuel shortages have led to widespread power cuts across Gaza City. That, in turn, has caused problems in pumping water to homes, and sewage to treatment plants.

Israel is preventing many aid workers, and all journalists from entering Gaza too, so our interviews have had to be conducted over the telephone.

"I never thought we would see days like this," says Monther Shublak, head of Gaza's water authority.

"The water system was severely stretched even before this crisis, but now, things are much worse.

"For the last four days, around 40% of people in Gaza City have had no access to running water in their homes at all."

"People ask me 'When will we get water?' I simply can't answer them," Mr Shublak says.

"But we are putting all of our resources into sewage pumping. The health consequences of that system totally failing are too worrying to think about, but it could happen unless things change."

Alongside attacks by its military, Israel's government says its Gaza closure strategy aims to deter Palestinian militants from firing rockets across the border at Israeli towns.

It also wants to choke Hamas, the Islamist faction in charge of Gaza, an enemy Israel sees as one of its most deadly.

But the rockets keep being launched and Hamas shows few signs of losing its grip on power.

Question of blame

There is much discussion among Palestinians as to why this sudden increase in pressure on Gaza is happening now.

Some say Israel is preparing for a big invasion; others feel there is an element of political posturing ahead of an Israeli general election in February.

Many will tell you that they feel a time of deep division in Palestinian society is being taken advantage of.

Few take Israel's explanation, that it is only protecting its citizens from the horror of rocket attacks, at face value.

"Isn't it enough that their army kills the people who fire rockets?" asks Mr Nasser.

"We are not responsible, so why are we all being punished? It makes no sense."

He talks of the long-term impact on children in Gaza, including his own, aged six, five and two.

"It's getting harder for us to answer our childrens' questions about the situation, without instilling hatred in their minds about the people responsible for our suffering," he says.

He does not just mean the Israeli government.

"People here see everyone as responsible for their miserable lives. They see Israel closing Gaza, but they also see people around the world doing nothing.

"They see Hamas making things worse by using the blockade as an excuse not to be accountable, and they do whatever they like.

"People see the silence of the PA, [the Fatah-dominated Palestinian government in the West Bank] and blame them too," he says.

"It's so hard to see where the hope is, and so hard to stop these conditions breeding more hatred."