As a cold rain fell on the devastated community of Ryongchon, relief workers warned that more food, blankets and medicine were needed immediately in the impoverished nation.
Video released by the United Nations showed patients squeezed two to a bed in shabby hospitals, with compresses over their eyes and facial injuries from being struck by a wave of glass, rubble and heat in Thursday's blast.
Aid workers said North Korea was short of even basic equipment like sutures and intravenous drips, and that donated goods were being used up as quickly as they could be supplied.
The Red Cross distributed a three-month supply of antibiotics, anesthetics and bandages to North Korean hospitals over the weekend, but "according to the hospitals, they have already used these medical supplies and have requested more," said Niels Juel, an official for the agency who is based in Beijing.
The casuality toll stood at 161 dead and more than 1,300 injured by the explosion of oil and chemicals, aid agencies said.
"The overall health system ... is very strained," said Brendan McDonald, a U.N. aid coordinator in Pyongyang, the North Korean capital. Electrical power and water supplies are "all inadequate," he said.
The Red Cross launched an emergency appeal Monday for $1.25 million in aid for North Korea. "Some families have lost all their belongings," Juel said. "Also, the water and sanitation system in that area would need to be restored."
Days after the catastrophe, details were still only trickling out from the secretive, communist North. Aid workers who first arrived in Ryongchon on Saturday described seeing huge craters, twisted railroad tracks and scorched buildings.
Nearly half of the dead were children in a school torn apart by the blast, and the disaster left thousands of residents homeless, the aid workers said.
One worker who toured a hospital in the nearby city of Sinuiju said that injured children lay on filing cabinets because there weren't enough beds. The hospital was "short of just about everything," said Tony Banbury, Asia regional director for the U.N. World Food Program, after his visit Sunday.
The United States is giving the Red Cross $100,000 to help the homeless, the White House said Monday.
The administration also is prepared to provide medical supplies and equipment, as well as a team of specialists in emergency medicine to work with the North Koreans, if needed, a White House statement said.
Despite differences with communist North Korea over its weapons programs and authoritarian policies, the United States has been the largest provider of food aid to the economically beleaguered Asian country.
"We provide all humanitarian aid in disasters based on need without regard to political issues," White House press secretary Scott McClellan said in a written statement.
Japan, Russia, Australia are among the countries that have already offered to send supplies. Neighboring China dispatched truckloads of tents, blankets and food across its border over the weekend.
But North Korea's border with South Korea remained sealed.
At a cargo depot near Seoul, Red Cross trucks loaded with medical supplies, bottled water, clothes and packages of instant noodles were awaiting the green light. But North Korea was hesitant Monday about allowing them across the Demilitarized Zone that has separated the two Koreas for over half a century.
The Pyongyang government also didn't respond to a South Korean offer to unload ships carrying relief goods at ports near Ryongchon.
Officials from North and South Korea planned to meet in the northern city of Kaesong on Tuesday to discuss relief operations.
"It is most important to have the relief goods arrive in the site of the explosion as quickly as possible," said South Korean Prime Minister Goh Kun. "By land or by sea, a quick means of transportation should be found."
The South Korean public has also mobilized, with civic groups and the news media launching donation campaigns.
The Koreas were divided at the end of World War II. Their border remains sealed after the 1950-53 Korean War, which ended without a peace treaty.
North Korea's Communist government relaxed its normally intense secrecy as it pleaded for international help. It has blamed the disaster on human error, saying the cargo of oil and chemicals ignited when workers knocked the train cars against power lines.