Updated

Pakistani authorities arrested 13 Islamist militants in separate raids that police said Monday foiled major terrorist attacks and provided clues to how drug sales to Asia and the Persian Gulf help fund the Taliban.

Police seized heroin and bomb-making material in one bust in the southern city of Karachi, the country's commercial center and a hotbed of extremist activity. In the country's east, authorities captured a main Taliban recruiter of suicide bombers in one of two raids.

Nuclear-armed Pakistan is battling Taliban and Al Qaeda-linked militants blamed for scores of terrorist attacks over the last two years. On Aug. 5, the campaign got a major boost when Pakistani Taliban leader Baitullah Mehsud was believed to have been killed in a U.S. missile strike close to the Afghan border, where the militants are strongest.

Police in Karachi arrested seven members of the banned Lashkar-e-Jhangvi movement in a raid Sunday in the teeming port city of more than 16 million, police officer Fayyaz Khan said. The al-Qaida-linked movement is blamed for two failed assassination attempts against former President Pervez Musharraf and the beheading of Wall Street Journal reporter Daniel Pearl.

The Karachi cell was planning attacks on government officials, police and offices of intelligence agencies in the city, police officer Saud Mirza said. He would not be more specific about the targets, saying it could jeopardize an ongoing investigation.

Police seized 4.5 pounds of heroin plus three suicide vests and 33 pounds of explosives in the raid, police said.

Khan said the gang shipped the heroin to China, Malaysia, Singapore and United Arab Emirates, and brought the profits back to Pakistan. From there, he said, the money headed to the border with Afghanistan, which supplies 93 percent of the world's opium, the main ingredient of heroin and one of the main sources of Taliban funding.

Part of the profits were transferred to a Taliban commander named Abdul Samad in Chaman, an area on Pakistan's southwestern border with Afghanistan, he said.

"It is often talked about that militants do drug business to finance their needs, but this is the first time we have arrested such a gang," Khan told The Associated Press.

In the eastern Pakistani city of Sargodha, police arrested six militants Monday in two raids, police chief Usman Anwar said.

He said they were linked to Mehsud's Taliban and had planned to launch strikes next week on at least two places of worship, foreigners, politicians and minorities in the city. He said the raids had "prevented mayhem," giving no more details.

Among the six was Zaid Mustafa, who Anwar said recruited potential suicide bombers for training in Afghanistan and who is suspected of providing logistics, explosives and other support for terror attacks in Lahore, Karachi or Rawalpindi.

"Every time the Taliban in tribal areas wanted to carry out an attack in Pakistani cities, Zaid would certainly be on board," Anwar said.