|The protesters chanted slogans against president Saleh, including: 'Down with the president's thugs' [Reuters]
Protests in Yemen are spiralling out of control as they enter their sixth consecutive day, with pro-democracy protesters and government loyalists clashing in Sanaa, the capital, and in the southern port city of Aden.
A 21-year old protester was shot dead after clashes broke out between police and demonstrators in Aden, his father said on Wednesday.
Mohammed Ali Alwani was among two people hit as police fired shots into the air to try to break up around 500 protesters gathered in the port town.
Despite thousands of police being deployed across Sanaa, dozens of students demanding the president's ouster clashed with government supporters at Sanaa university.
Demonstrators were set upon by hundreds of loyalists armed with batons, stones and daggers, shortly after they set off from the university towards al-Sabiine square.
Some protesters fled while others hurled stones, and clashes later spread to the university campus.
The Reuters news agency said one student had been wounded in the clashes while AFP said three journalists were beaten up by supporters of Ali Abdullah Saleh, the president, near the university.
Protesters accused government "thugs" of "brutally" attacking them and charged the assailants including plainclothes police.
"The thugs and supporters of the ruling party ... [want to] massacre" the students, Radwan Masud, head of the university's student union, said.
He vowed that the students will "continue their revolt and will not be hindered by the ruling party's actions".
Similar clashes have taken place on a daily basis this week as protesters, inspired by uprisings in Tunisia and Egypt, demand Saleh's ouster.
On Tuesday, police in Sanaa dispersed clashes between regime supporters and a crowd of anti-government protesters that left three wounded. Similar scenes also occurred in Taez, south of the capital.
On Monday, rocks and batons flew in the capital as the protesters, mainly students and lawyers, clashed with police and Saleh's supporters. Police also clashed with protesters in Sanaa on Sunday.
A sit-in by hundreds of judges demanding greater independence of the judiciary and the ouster of the Supreme Judicial Council, meanwhile, went into its second day outside the justice ministry in Sanaa.
The judges who have poured into Sanaa from around Yemen said they want all the members of the Supreme Judicial Council, including the justice minister, to be sacked. They also are demanding higher salaries.
Several checkpoints have appeared on the streets leading to Sanaa's presidential palace, and many have been blocked with razor wire.
The protests have been continuing despite Saleh's pledge not to seek another term in 2013.
On Monday, a 3,000-strong throng of demonstrators, clad in black robes, clashed with police and pro-government supporters in Sanaa.
Military ties between the US and Saleh's administration have grown stronger in recent months, as the country struggles with the increasing militancy of a secessionist movement in the south, as well as unrest provoked by rising food prices, unemployment reaching 40 per cent - and demands for human rights to be recognised.
The US is shortly to embark on a $75m project to train Yemen's counterterrorism unit, US officials say.
Saleh became leader of North Yemen in 1978 and has ruled the Republic of Yemen since the north and south merged in 1990.