KABUL, Afghanistan (AP) – The deadliest three weeks of violence since the fall of the Taliban has left more than 500 people dead, the U.S-led coalition said Saturday.

The toll included at least 44 deaths last week.

Meanwhile, a top Afghan intelligence agent narrowly survived a bomb attack on his convoy that killed three other people near the capital, Kabul. Fighting elsewhere killed six insurgents and three police on Saturday, officials said.

Much of the recent Taliban fighting is believed funded by the country’s $2.8 billion trade in opium and heroin – about 90 percent of the world’s supply.

The daily violence has raised fears of a Taliban resurgence almost five years after the Islamic extremists were driven out by a U.S.-led invasion for harboring al-Qaida.

A coalition spokesman, Lt. Col. Paul Fitzpatrick, said there would be no letup in attacks on militants.

“We will not be deterred from our mission to provide a safe and secure environment to the Afghan people,” he said in a U.S. military statement.

In an apparent attempt to kill Kabul’s director of government intelligence, Humayoon Aini, a bomb ripped through the first car in his convoy late Friday, killing a local politician and two other people, said Kabul’s police chief, Amanullah Ghazar.

Aini, who was in the second car, was unhurt, Ghazar said. The intelligence director had been returning to the capital from a meeting in a neighboring district, Ghazar said.

In southern Zabul province Saturday, Afghan troops battled insurgents for hours, killing two and capturing two, before dozens of others fled into nearby mountains, army commander Gen. Rehmatullah Raufi said.

Of the more than 44 militants killed last week, more than 30 died in a battle with Canadian and Afghan troops in Zabul province on Monday, a coalition statement said.

The Afghan Interior Ministry announced that in the past week 9 tons of opium and 88 pounds of heroin have been seized in raids across the country.

The United States, Britain and other countries are spending hundreds of millions of dollars fighting the drug business.