Bahrain has postponed the trial of prominent human rights activist, Maryam al-Khawaja, and ordered that she remain in custody for an extra 10 days, despite the UN calling for her release.

Al-Khawaja was arrested as she arrived in the country on August 30, and charged with allegedly assaulting a lieutenant and a policewoman after she refused to hand over her phone during a search.

In a hearing on Saturday, Khawaja appeared in court with her arm in a sling, and denied the charge of assaulting police at Manama airport. She called the accusation "vindictive and fabricated".

Her lawyer, Mohammed al-Jishi, told the AFP news agency, that the judge ordered Khawaja be kept in custody on that charge, and could face a maximum of two years in jail.

Bahrain's prosecution said that it was close to finalising its investigation.

It said witnesses reported Khawaja hitting police officers after "they asked her to hand in her mobile phone as per arrest procedures".

Khawaja, the co-director of the Gulf Centre for Human Rights, returned to Bahrain to visit her jailed father, the prominent rights activist Abdulhadi al-Khawaja.

Her father is on hunger strike in protest against a life sentence he is serving in connection to 2011's Shia-led anti-government protests.

Maryam al-Khawaja has been active in criticising Bahrain authorities from abroad and has regularly met US Congress members since giving evidence at a congressional hearing on Bahrain.

"Maryam is really being targeted because of her international advocacy work," Brian Dooley, director of Human Rights First, told the AFP news agency.

On Friday, the UN called on Bahrain to release al-Khawaja and expressed concern about "ongoing violations" of freedom in the country.

Ravina Shamdasani, a spokeswoman for the UN high commissioner for human rights, said the agency was "seriously concerned" that Khawaja had been arrested.

"We urge the government to take immediate steps to release Ms Khawaja and all human rights defenders and individuals detained for the peaceful exercise of their rights," she said in a statement.

Bahrain has experienced regular protests since 2011 led by Shia Muslims after similar unrest erupted in Egypt and Tunisia.

Shia make up the majority of Bahrain's population. They complain of political and economic marginalisation, an accusation the government denies.

(Aljazeera)