The death toll from a fire at a Moroccan prison has risen to 50 after another prisoner succumbed to his injuries, the MAP news agency reported.89 others were injured when a fire raged through a prison in El Jadida, south of the Moroccan capital Rabat, reviving a debate about conditions in the north African kingdom's notoriously overcrowded jails.

Many of the 50 killed in the blaze at Sidi Moussa Prison, on the outskirts of the Atlantic coastal town of El Jadida, were inmates who died of smoke inhalation.

The fire, said to be the worst ever in Morocco's overcrowded prisons, broke out in one of the jail wings at around 1:30 am (0130 GMT) and smoke quickly filled three other sectors.

Firemen brought the blaze under control at around 3:00 am.

Six of the injured were still in serious condition, MAP said, citing local authorities, while around 40 were expected to be discharged "in the next few hours" from El Jadida's Mohammed V hospital, where all the casualties had been taken.

Abderrahim Jamai, the head of the Moroccan Prisons Observatory (OMP), a non-governmental organization with representatives from several human rights groups, said the blaze was the worst ever in a Moroccan prison.

The OMP leader called the fire a scandal that "most certainly resulted from a lack of maintenance" in Morocco's notoriously overcrowded prisons, known for their appalling conditions.

A member of the Moroccan Human Rights Association (AMDH), shocked by the high death toll, told AFP the incident "reflected the prison administration's and local authorities' negligence."

In May last year, OMP issued a stern warning on conditions in Moroccan prisons, calling "overcrowding ... a bomb that forces us to think about alternative solutions to incarceration."

That report said that in several prisons, 80 inmates are housed in cells of of only 60 square meters (700 square feet).

Only one out of Morocco's 44 pentitentiaries -- Khenifra Prison, in central Morocco -- has an acceptable population density, the report said.

All together, Morocco's jails have the capacity to house some 39,000 prisoners. Sidi Moussa was built to take in 1,000 inmates, but more than 1,300 prisoners were being detained there, MAP said Friday.

The prison population in Morocco has nearly doubled in the past 10 years, swelling from some 31,230 detainees in 1991 to more than 57,300 last year, Hassan Hamina, a prison administrator, said on October 21.

OMP said in a recent report that the number of prisoners had increased by a further 12 percent this year.

Every year, some 5,000 new detainees swell Morocco's prison population, but the jail construction programme in the north African kingdom is unable to keep pace with the constantly rising numbers, the report said.

MAP had reported earlier that an electrical short circuit had caused the fire at Sidi Moussa, but said later Friday that the cause of the blaze was unknown.

In August, two prisoners died and some 20 were injured in a fire at a jail north of Rabat. That blaze was blamed on a short circuit in the electricity supply.

King Mohammed VI has expressed his condolences to the families of the victims of the Sidi Moussa blaze.

Outgoing Prime Minister Abderrahmane Youssoufi and his recently named successor Driss Jettou visited the scene of the blaze Friday, after the king had asked them to travel there.

A government inquiry has been launched into the cause of the blaze, with results promised as soon as possible.

PHOTO CAPTION

Crowds gather at the main entrance, seen in background, of the Sidi Moussa jail where at least 49 inmates were killed and about 90 others were injured when a fire broke out early Friday Nov. 1, 2002, in El Jadida, 90 miles south of Casablanca, Morocco. Causes of the fire were unknown. The Moroccan flag flies over the prison in background. (AP Photo/Abdeljalil Bounhar)