Police in Hong Kong seize explosives ahead of major civil rights protest

HONG KONG — Police in Hong Kong discovered a stash of a powerful homemade explosive as the semiautonomous Chinese city readied for another major pro-democracy rally Sunday.

Police said they found 4.4 pounds of TATP and arrested a man in a raid on a commercial building late Friday. TATP, or tri-acetone tri-peroxide, has been used in terrorist attacks worldwide.

Materials voicing opposition to an extradition bill that has sparked more than a month of demonstrations in Hong Kong were found at the site, local media said, but a police spokesman said no concrete link has been established and that the investigation is continuing.

In a rally that aimed to counter the pro-democracy movement, thousands of people filled a park in central Hong Kong on Saturday to support the police, who have been accused of using excessive force on protesters. Some waved Chinese flags, and a giant screen behind the stage for speakers read “Safeguard Hong Kong.”

Many wore white, heeding a call by organizers, and the demonstrators did not wear masks or helmets, public broadcaster RTHK said. The anti-extradition law activists wear black and don protective gear against police pepper spray and batons.

Organizers said 316,000 people took part in the demonstration, while police put the turnout at 103,000.

Alick McWhirter, a senior bomb disposal officer, said the seizure of the explosives Friday was the largest of its kind in Hong Kong and called it troubling that such a dangerous substance was being made in a homemade laboratory in the middle of the city.

“It puts at risk everybody within the building. It puts at risk bystanders outside,” he told reporters.

Police spokesman Tse Chun-chung said more arrests may follow.

Police have erected large barricades near government headquarters in...