* Bomb-laden cars, vans found in different locations in Kano
* Boko Haram attacks Friday killed 186 people - police
* Policeman, four sect members killed in Maiduguri (Adds death toll of 186, police statement)
By Mike Oboh and Ibrahim Mshelizza
KANO/MAIDUGURI, Nigeria, Jan 23 (Reuters) - Nigerian police said they found cars and vans filled with explosives in the northern city of Kano on Monday, three days after the Islamist sect Boko Haram carried out bomb and gun attacks there.
Security in Nigeria's second largest city has been beefed up since Friday when bomb attacks and gun battles between the sect and police killed at least 186 people.
"The police were on a stop-and-search today and in two of the checkpoints, the Boko Haram members on sighting the checkpoints abandoned their vehicles and ran," a high-level police officer told Reuters, asking not to be named.
"The vehicles were later checked and the cars were loaded with explosives. Two brand new Hilux open pick-up vans were also found packed with explosives in the Bompai area of Kano."
Boko Haram, a Hausa term meaning "Western education is sinful", is loosely modelled on Afghanistan's Taliban.
The sect focuses its attacks mostly on the police, military and government, but has attacked Christians more recently. It says it is fighting enemies who have wronged its members through violence, arrests or economic neglect and corruption.
"The command informs the general public on the sad state of security and ugly incident on Friday. It was a day on which some extremists launched sporadic attacks with bombs and assault rifles in parts of the state capital," the Kano commissioner of police, Ibrahim Idris, said in a statement on Monday.
"29 policemen, three state security service officers, two immigration officers, one custom officer, one journalist and 150 civilians were killed by the extremist."
He said the attacks were triggered by 10 cars loaded with improvised explosive devices (IED) and more than 300 smaller, drinks can-sized IEDs around the city.
In Maiduguri, the home town of Boko Haram hundreds of kilometres east of Kano, a policeman was shot dead by members of the sect. On Sunday, the military killed four Boko Haram gunmen in Maiduguri and found explosives in their car.
"The policeman was on patrol along with his colleague in a vehicle when the Boko Haram opened fire and shot him dead," said Simeon Midena, the commissioner of police. "As usual the killers just disappeared into the crowd."
The joint military task force has increased its defences and widened its patrols in Maiduguri in recent days.
"Four members of Boko Haram sect involved in killings in Maiduguri and environs have been under surveillance of security agencies and have been shot dead in Pomomari area of Maiduguri yesterday (Sunday)," Colonel Victor Ebhaleme, an officer in the joint military task force, said earlier in a statement.
"Various IED materials prepared for detonation were recovered from their car."
Boko Haram, which was formed in Maiduguri in 2002, has killed hundreds of people in the last year, mostly in and around its home state of Borno, though its attacks have been spreading across the north of Africa's most populous nation.
President Goodluck Jonathan has been severely criticised for not getting a grip on a group he says has infiltrated the police, military and all areas of government.
The sect originally said it wanted sharia (Islamic law) to be applied more widely across Nigeria. (Reporting by Ibrahim Mshelizza; Additional reporting by Felix Onuah in Abuja and Mike Oboh in Kano; Writing by Joe Brock; editing by Robert Woodward)