Pakistan (search) and India (search) made an unprecedented agreement Sunday to open their heavily militarized border in disputed Kashmir to aid the flow of relief goods and reunite divided families in the aftermath of South Asia's colossal earthquake.

The head of the U.N. Children's Fund (search) warned Sunday that thousands more could die in the region from disease, diarrhea and injuries if survivors do not receive more medical attention, tents and blankets as the harsh Himalayan winter bears down on them.

About 80,000 people were killed in Oct. 8 quake, most of them on the Pakistani-side of divided Kashmir. More than 1,300 people died on the Indian side of Kashmir. An estimated 800,000 survivors still lack basic shelter with tents in short supply. Relief officials say 600,000 tents are still needed.

The two countries issued a joint statement after marathon talks to establish five crossing points along the Line of Control (search) that has divided the Himalayan region for nearly six decades. The neighbors have fought two wars over Kashmir.

The move marks a significant step forward in the countries' tenuous relationship, marred by decades of suspicion and rivalry. Opening the border in predominantly Muslim Kashmir is particularly sensitive for India's government, which has been fighting a 16-year insurgency by Islamic militants who want Indian Kashmir to be independent or united with Pakistan.

The agreement came after a series of explosions in India's capital Saturday night killed at least 61 people in carnage that Indian leaders blamed on unspecified terrorists. Pakistan's government condemned the bloodshed.

Analysts hailed the politically significant border deal, praising the two countries for continuing to thrash out the accord despite the bombs in New Delhi (search).

"There was fear. It had been a practice in the past (in India) to blame Pakistan for anything like that. But this time nobody blamed Pakistan," said Khalid Mahmood, a research analyst at Islamabad's Institute of Regional Studies.

U.N. humanitarian coordinator in Muzaffarabad Rashid Khalikov also welcomed the Pakistan-India accord, calling it "a good step in this disastrous condition. It will open an opportunity to extend humanitarian help to the affected people in the far-flung villages alongside the Line of Control."

The United Nations, along with other relief groups, have been scrambling to get relief supplies to the estimated 3.3 million left homeless in the quake, many of them in remote mountainous areas, before the harsh winter sets in.

In her first tour of Pakistan's quake-ravaged Kashmir, UNICEF (search) Executive Director Ann Veneman casualties could mount if the survivors do not get more aid soon.

"The fear is that we could lose thousands of people additionally to diarrhea, disease and injuries that are not treated," she told the Associated Press. "It's absolutely urgent that as much aid gets in as possible."

Though donors have pledged hundreds of millions in aid to fund the international relief effort, only a fraction has been received. The U.N. has warned its emergency reserves are very low, and that helicopters could be grounded within a week without more funding.

"We have funds sufficient for the next couple of weeks but in order to continue this operation, we need funds immediately as all reserves are being used and if funds are not generated, we would be compelled to scale-down our activities," Khalikov said.

The border openings will begin Nov. 7. Relief goods can be sent in either direction and handed to local authorities at the crossings, the joint statement said. Civilians will be allowed to cross on foot, with priority given to families divided by the border.

In Muzaffarabad, quake survivors such as shop owner Shiraz Nawaz, 26, said the agreement will allow families divided by the border to reunite.

"My cousins want to come here from Srinagar to express sympathies over my father's death. This agreement will help them. This will increase the chances for relatives to meet in this atmosphere of grief," he said.

Procedures for crossing the border will be similar to those implemented earlier this year when bus service resumed between the two capitals of disputed Kashmir, Muzaffarabad and Srinagar. People wanting to cross would have to apply for a permit from government officials on either side to verify their identities.

Crossings will be allowed at the Pakistani-Indian border towns of Nauseri-Teethwal, Chakothi-Uri, Hajipur-Uri, Rawalakot-Poonch, and Tattapani-Mendhar.

Since the quake, India has delivered tons of supplies to Pakistan, and on Wednesday offered $25 million. India is setting up three relief camps on its side of the border where Pakistani quake victims can get medical help, food and relief supplies.