The United Nations warned that 800,000 people remain without shelter more than two weeks after South Asia's colossal quake, and repeated its urgent appeal for more aid. As powerful aftershocks continued to rattle the region, a top US commander said the United States would step up its relief efforts. US Gen. John Abizaid, head of the US Central Command, after a tour of the quake zone Sunday said he "saw devastation everywhere" and that 11 more Chinook helicopters would join the existing 17 US helicopters and the Army's only Mobile Army Surgical Hospital, or MASH, in relief efforts. In an unusual convergence of appeals, al-Qaida's deputy leader, Ayman al-Zawahri, urged Muslims to send as much aid as they could to quake victims in Pakistan, despite President Gen. Pervez Musharraf's alliance with the United States in its war on terrorism. Meanwhile, Pakistan and India inched closer to a deal in which they would put aside their long-standing dispute over the Kashmir region for the sake of helping the quake victims, allowing them to cross the disputed border. The need to speed up relief efforts took on greater resonance Sunday as a powerful aftershock - one of hundreds since the Oct. 8 temblor - rocked Pakistani-held Kashmir, the region hardest hit by the initial quake. No one was killed in that aftershock, but an earlier tremor Sunday killed five people in Afghanistan's eastern Zabul province near the Pakistan border.