Police in Hong Kong have detained several pro-democracy activists on the anniversary of the Tiananmen Square massacre.

Authorities have banned public commemoration of the 1989 incident, which saw China crush peaceful protests in Beijing with tanks and troops.

Among those detained was 67-year-old Alexandra Wong, a prominent campaigner nicknamed "Grandma Wong".

Amid a tense evening in Hong Kong, she was arrested while carrying flowers near Victoria Park, where vigils had been held for decades.

The leader of one of Hong Kong's main opposition parties was among those arrested. Chan Po Ying, a veteran pro-democracy activist who heads the League of Social Democrats party, was holding an LED candle and two flowers.

Mak Yin Ting, former head of the Hong Kong Journalists Association, was also detained and subsequently released. Police later said they had made one arrest and taken 23 people to police stations for investigation.

Events to mark the 1989 massacre in Beijing are banned in mainland China.