Endless blocks of apartments as far as the eye can see. Violent, teeming slums that police won't enter. A porous coastline where fugitives can slip away to Arab shores.
If you're an Al Qaeda terrorist on the lam, immense, poorly regulated Karachi may be the perfect place to hide. And increasingly, say Pakistani officials charged with hunting down foreign extremists, that's precisely what they're doing.
When thousands of Al Qaeda fighters fled Afghanistan after the fall of the Taliban regime, they were widely expected to lie low in familiar territory: the isolated hills and valleys of Pakistan's lawless northern tribal belt. But joint US-Pakistan forces probing for terrorists there haven't netted a single big fish, even though they've rounded up more than 400 low-level fighters.
Almost one year after the Afghan regime change, it appears that terrorist fugitives have instead opted for the anonymity of Pakistan's southern urban jungle. Abu Zubaydah, the terror network's chief of operations, was nabbed in industrial Faisalabad last March. And Karachi police emerged with Ramzi Binalshibh, a Yemeni believed to be a chief planner in the Sept. 11 attacks, after a lengthy shootout at an apartment complex last month.
Pakistani intelligence and police officials now admit that the man they were actually looking for that day was Khalid Shaikh Mohammed, an even more senior figure in the Al Qaeda network, who is considered the head of its Pakistan cell.
"We had some information that terrorists were there [at the apartment]. An encounter ensued and two men were killed" in addition to Ramzi's arrest, says Sayed Kamal Shah, the police inspector-general for southern Sindh province.
Some say Shaikh Mohammed may have been one of the two men killed in the shootout, though authorities say they have not identified either body. Muslims bury bodies within 24 hours, and Pakistan's forensics services tend to be inadequate.
Shaikh Mohammed's name appears on the FBI's list of most wanted terrorists, along with that of Ayman Al-Zawahiri, Osama bin Laden's second in command, whom officials have also sought here. Senior police officials and intelligence agents say that Mr. Zawahiri, may have slipped out of Pakistan from here. And there are persistent, though unconfirmed, reports that dozens of Al Qaeda fighters, possibly including Zawahiri, escaped in launches that steamed east to Bangladesh or west to the Middle East.
Other reports put top Al Qaeda fugitives in hideouts scattered between Karachi and Pakistan's northwest desert city, Quetta, according to intelligence officials.
"We have conducted many searches, and we have found nothing yet," says a top Pakistan police official.
Senior Karachi officials stress that, despite continuing intelligence indicating Al Qaeda presence here, remarkable police work has put the brakes on a cycle of sectarian violence that once terrorized this city.
Karachi police have arrested most of the suspects in the kidnap and brutal murder of Wall Street Journal reporter Daniel Pearl, as well as the militants charged in the June 14 bombing of the US Consulate.
Dozens of local extremists from groups that have links to Al Qaeda have been detained, a step which authorities feel will make it harder for Al Qaeda members to find safe haven here.
"Our continuous efforts have proved quite successful," says Mr. Kamal Shah. "I feel [Al Qaeda] would find it quite hard to hide here now."
Investigators tracked backward through phone records to locate the web of extremists behind Mr. Pearl's murder. The FBI is providing assistance in monitoring cellular phones and land lines to track Pakistani extremists, some of whom are known to have met when they trained in Al Qaeda camps in neighboring Afghanistan.
"These were local gangsters who made friends in Afghanistan," says Jameel Yusuf of the Citizen Police Liaison Committee. "They are now being used to hit back at Pakistan for its alliance with [Washington]."
The joint efforts by US and Pakistani investigators has had tremendous success in rounding up extremists, both sides say.
But finding Al Qaeda operatives in the cities has proved more difficult, and may be an indication that terrorist agents are not operating in Karachi so much as lying low. Various senior Al Qaeda members being tracked, say Pakistani officials, are known to change locations every few days and wear disguises.
That's why local intelligence will be crucial for future efforts to succeed. However, that is proving difficult in a crime-ridden megalopolis where public trust in authority is low, according to surveys the police themselves have conducted, and where police are both underpaid and overworked.
As well, there are ominous signs that extremist groups are regrouping.
On Oct 16, a series of parcel bombs delivered to Karachi police inspectors charged with sniffing out terrorists exploded simultaneously. At least nine men were wounded.
An e-mail claiming responsibility on behalf of militant Muslims was received by a major daily newspaper here and a local news agency, according to reports. The e-mail said the bombs were "a warning to those police officers involved in operations against 'Mujahideen' [holy warriors] at the behest of the Americans."
It said further attacks could be expected against "anti-Islam police officers and other infidels."