4 charged after potential bomb-making chemicals found at northwest London, Ont., home

Four people face multiple charges after police say a trespassing call on Western University's campus last weekend led to the discovery of chemicals allegedly capable of making explosives in a nearby London, Ont., home.

The London Police Service said Tuesday that the chemicals were located in the University Heights neighbourhood west of campus. A heavy police presence remained, with a bomb disposal unit on standby and an excavator parked near the corner property at 212 Chesham Place.

The multi-day probe began Saturday at Western University when officers were called around 1:40 a.m. ET to assist campus police with a trespasser who was taken into custody, police said.

The man, identified as a 27-year-old from Ottawa, was arrested by campus special constables after a foot pursuit and a loaded handgun was seized, police said.

Officers later learned a second man had been involved, and further investigation led them to the home on Chesham Place where two more people were arrested, police said in a statement.

Speaking with reporters at the scene, Sean Travis, acting detective superintendent with London police, said observations were made in the home that "created concern about chemicals that could be used to create explosive devices, not that devices were located."

"That isn't the sole source of explanation for the presence of these chemicals, but they are to be treated in a way that handling them is important for the safety of all involved, which includes the emergency personnel that's present, as well as the surrounding community."

Travis said police could not confirm if there were any concerning messages or letters found in the home, as the investigation is underway, but confirmed a drug lab is not suspected. He said he wasn't aware whether anything had been stolen from the university.

Fei (Frank) Han, 25, of London and Feiyang (Astrid) Ji, 21, of London were each charged with unlawful possession of explosives.

Jerry Tong, 27, of Ottawa was charged with six offences, including carrying a concealed weapon, careless use of a firearm, possessing a loaded regulated firearm, resisting arrest, break and enter with intent, and occupying a motor vehicle with a firearm.

London resident Zekun Wang, 26, was charged with break and enter with intent and occupying a motor vehicle with a firearm.

Han was scheduled to appear in court on Thursday, according to court records. Updated appearance dates were not available for Ji, Tong or Wang.

Investigators have been at the home since Saturday, police said.

Several neighbours told CBC News they did not personally know any of the residents at the home, but many believed them to be students.