Pakistani authorities have temporarily suspended helicopter relief operations to earthquake-hit areas north of Islamabad because of torrential rains.
Helicopters were ferrying supplies to towns and villages that are inaccessible by road because of landslides triggered by Saturday's 7.6 magnitude earthquake.
Earlier, army convoys carried supplies to several devastated cities, including Muzaffarabad in Pakistani Kashmir, where hundreds of thousands of survivors have spent the past two nights in the open.
The government's official death toll remains at slightly over 20,000 people. But a senior army official close to the rescue operations told the Associated Press that, according to their estimates, the death toll is between 35,000 and 40,000 people.
Across the line of control, in Indian Kashmir, officials say the quake death toll has surpassed 1,300 people, and could rise further. India's military is leading rescue operations and the distribution of supplies to remote villages.
Indian Prime Minister Manmohan Singh visited the affected area Tuesday, and assured survivors of government help in rebuilding their lives. Mr. Singh also pledged more than $110 million in additional emergency relief aid for the region.
Some information for this report provided by AP, AFP and Reuters.