Hong Kong's leader has claimed that "external forces" are participating in student-led pro-democracy protests that have occupied parts of this financial capital for more than three weeks, but provided no evidence to back his accusation.

Chief Executive Leung Chun-ying's statement in a televised interview Sunday was the first time he has alleged foreign involvement in the unrest, echoing accusations by China's central government, which also has not backed them with any evidence. Leung's statement comes just before his government is scheduled to hold talks with student leaders on Tuesday.

When asked on the "Newsline" program about a Chinese official's comments on outside involvement, Leung said, "There is obviously participation by people, organizations from outside of Hong Kong." Leung added that the foreign actors came from "different countries in different parts of the world," but didn't specify which countries.

The Hong Kong Federation of Students immediately rejected the accusations, with Secretary General Alex Chow saying Leung was "just making it up."

"He's the chief executive, he's an accountable official," Chow told reporters. "If he's putting forward these accusations, then we hope he also puts forward the evidence. But he shouldn't just say that foreign powers are meddling without evidence."

Protesters, mostly young college students, are pressing for a greater say in choosing the semiautonomous Chinese city's leader in an inaugural direct election, promised by Beijing for 2017. They oppose Beijing's ruling that a committee stacked with pro-Beijing elites should screen candidates in the election. That effectively means that Beijing can vet candidates before they go to a public vote.

In what has become a daily pattern, the police have driven away the students from some streets during the night, only to see them regroup and occupy the areas and resume their sit-ins.  The protests stretched into their fourth week Monday with thousands of demonstrators camped out in downtown Hong Kong and two other sites in this city of 7.2 million.

After two nights of violent clashes, protesters and police settled into an uneasy peace in the densely commercial Mong Kok district after two pro-democracy legislators, Fernando Chiu and Claudia Mo, arrived late Sunday night and helped calm tensions.

Earlier Sunday, police spokesman Steve Hui said an unnamed 23-year-old was arrested on the charge of accessing a computer "with criminal or dishonest intent" and unlawful assembly. Hui said the suspect had "incited others on an online forum to join the unlawful assembly in Mong Kok, to charge at police and to paralyze the railways."

It was the first arrest for online protest activity since the demonstrations began.

Police also said Sunday that 33 people had been arrested during the protests on common assault, criminal damage and other charges.

Nearly 300 people have been taken to hospital emergency rooms with injuries related to the protests since Sept. 28, the city's Hospital Authority reported Monday.