London, May 12 : Police in Nepal have arrested more than 600 female Tibetan protesters, including many Buddhist nuns, after demonstrations in Kathmandu against China's crackdown in Tibet.

The protesters held three separate rallies in the city, but the Nepal Police moved quickly to quash anti-China demonstrations in the past few weeks, with officials saying that they will "not allow protests" that may harm the country's friendly relations with neighbouring China.

The Tibetan exiles have mainly been protesting in front of the United Nations offices and the Chinese Embassy in Katmandu. Security has been stepped up around the embassy, with hundreds of police lining the streets that lead to the building.

The United Nations and human rights groups have criticised Nepal for using excessive force to put down the protests.

Police official RP Dhamala confirmed that more than 600 protesters were held in detention centres in Kathmandu. This is the first time when such a large number of protesters were detained on a single day since Tibetan exiles began their protests in March against Chinese policies in Tibet.

Activists said they were planning a silent march to protest Chinese restrictions in Tibet, but police refused to allow the peaceful demonstration to take place. "Just to create what is happening in Tibet we wanted to do a silent march here, a peaceful silent march. Unfortunately even before we could start police started arresting people," The Telegraph quoted protester Doma Tsomo as saying.

Police have beaten protesters with batons and dragged them through the streets before making arrests.