PARIS, April 11 (Reuter) - Small groups of protesters against Chinese Premier Li Peng's official visit to Paris criicised Beijing on Thursday over nuclear tests and alleged repression of journalists.

Police detained 11 people, including the head of the press freedom watchdog Reporters without Borders (RsF), and a lone anti-nuclear activist who flew near the Chinese embassy.

RsF said its general secretary Robert Menard and three other members were arrested as they drove up to the embassy to demand the release of 17 reporters jailed in China. Five journalists covering the event were also detained. Police removed two trucks bearing protest banners.

Earlier, a Greenpeace activist defied a ban on flying over central Paris and flew a motorised hang-glider near the embassy to demand an end to Chinese nuclear weapons tests.

Witnesses said the aircraft, trailing a banner demanding "China: stop testing now," flew over the Arc de Triomphe in an area with many embassies and diplomatic residences.

Witnesses said the pilot was detained when he landed in the nearby Monceau public park.

Li's first full day in Paris on Wednesday was marred by a diplomatic incident with French Prime Minister Alain Juppe over human rights, and by protests against alleged abuses in China and repression in Tibet and Li's role in the crushing of the 1989 Tiananmen Square democracy movement.

Some 2,300 demonstrators were barred from getting within shouting distance of the Chinese embassy, and 157 Amnesty International activists who demonstrated on the Champs-Elysees avenue were briefly held.