By Martin Patience
BBC News, Beirut
With stacks of tinned tomatoes, apricots and beans, hundreds of packets of rice, pasta and lentils, and crates of bottled olive oil, there is no shortage of food supplies in the windowless warehouse of Mercy Corps located in central Beirut.
But as volunteers pack brown boxes with enough food supplies for a family of 10 to survive for 15 days, Cassandra Nelson from the international relief organisation says she is frustrated about their inability to get the aid to those who need it most.
Providing aid is becoming an increasingly dangerous business
"The big challenge is how do you get the aid from the [Beirut] port to the people," she says standing outside the warehouse.
"There's no point in the food rotting at the port because that's not going to help anyone."
There is growing concern among international aid agencies about the hundreds of thousands of Lebanese who have not received aid in the south of the country.
As the conflict between Israel and Lebanon enters its third week, much of southern Lebanon is in ruins and dangerous to both reach and leave.
Aid convoys have been hit by Israeli air strikes in the south. Six Lebanese Red Cross paramedics were wounded in an Israeli strike on Sunday.
A UN humanitarian convoy of 10 trucks set off from Beirut on Wednesday to the city of Tyre in south Lebanon where aid is urgently required.
The UN received extensive co-operation from Israel to provide safe passage, but says that more aid needs to go south - and quickly.
For now, local and international aid agencies are focusing their relief operations on the towns and the villages close to Beirut where many of the refugees are gathered.
"It's completely frustrating, it's the biggest hurdle we're facing," says Ms Nelson, referring to the access to the south of Lebanon.
"We can't even go to the communities that we have worked with for 10 years."
Without clearance from Israel, Mercy Corps is delivering aid to villages located in the Chouf mountains.
One truck laden with 250 boxes of supplies climbed the steep, winding roads to deliver supplies to the village of Souk al-Gharb.
At the village's Modern Country School, 270 refugees from the south of Lebanon and Beirut's southern suburbs are staying.
Three-year-old Abrahim Jaber needs epilepsy medicine
The refugees say there are frequent electrical cuts and shortages of water. Many have not washed in days and about 20 people are living in each of the school's classrooms.
Until now, they have depended on handouts from the Lebanese government and Hezbollah, the militant Islamic organisation firmly supported by many of the people at the school.
But while they admit they are lucky to be away from the bombardment, some are desperate.
Layla Jaber's three-year-old son Abrahim suffers from epilepsy.
He has not taken his medication since the family fled the south of Lebanon over a week ago and Ms Jaber fears he might have an epileptic fit.
"We need people to bring him medicine," she says, tugging on her headscarf agitatedly.
"A doctor keeps coming and writing down his prescription, but he never returns with the medication."
She says the only small mercy is that Abrahim does not know he is sick.
He runs about the school's concrete playground without a care in the world.
But for Ms Jaber, the experience of fleeing her home with two young sons is all too much.
"We need help," she says. "We need the world to help."