Witnesses in Afghanistan report heavy explosions outside Kabul and other cities early Tuesday, as the American campaign aimed at flushing out Osama bin Laden's Al Qaeda terrorist network continues. U.S. Secretary of State Colin Powell is in the Pakistani capital for talks with President Pervez Musharraf.

Strong explosions were heard overnight near the Afghan capital, after what witnesses described Monday as the heaviest daylight strikes of the campaign, so far.

In a sign of how previous raids have crippled the Taleban defenses, the American-led strikes included a slow-moving, low-flying airship designed for ground strafing missions. It marks the first acknowledged use of special forces aircraft in the assault on terrorism.

U.S. planes also dropped leaflets telling Afghans the anti-terror alliance is aiming to help them. One of the leaflets shows a Western soldier shaking hands with an Afghan man, with messages of goodwill in local languages.

In Northern Afghanistan, anti-Taleban forces say they are poised to take the key town, Mazar-i-Sharif.

Meanwhile, diplomats are looking ahead to plan a possible post-Taleban government. A delegation representing the former king of Afghanistan, Zahir Shah, arrived yesterday to meet with Pakistani officials. Riaz Mohammed Khan is Pakistan's foreign ministry spokesman. "The context of the discussions are of course the situation in Afghanistan and the effort which has been intensified by the United Nations for promoting a broad-based government in Afghanistan," Khan said.

Secretary Powell is also in Islamabad for talks. Pakistan's government has been urging the United States to quickly finish the military campaign. The mainly-Muslim country has been facing demonstrations called by religious leaders opposed to the U.S. led raids, and pressure on the government has been rising as unconfirmed reports of civilian casualties mount.

Secretary Powell heads to New Delhi later Tuesday.