Ten of the 21 men convicted in the Madrid train bombings have begun a hunger strike to protest what they consider to be excessive jail terms, the government said Friday.

An official with the Spanish Penitentiary System said the 10 included two Moroccans — Jamal Zougam and Othman Gnaoui — who were convicted of murder and attempted murder and each sentenced to nearly 43,000 years in prison. Under Spanish law the most time they can serve is 40 years.

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The March 11, 2004, terror attacks on the Madrid commuter rail system killed 191 people and wounded more than 1,850.

Verdicts and sentences in Europe's worst Islamic terrorist attack were handed down Wednesday. Altogether, 21 of 28 people on trial were convicted of crimes ranging from weapons trafficking to belonging to a terrorist organization and murder.

The 10 hunger-strikers, now in prison in the Madrid area or in Alicante in the east, notified prison authorities in writing Sunday that they have stopped eating, although they still take liquids, the official said. Some of them staged hunger strikes during the trial, as well.

Rather than insist they are innocent, as they did during the trial, these men said in the written notices that their prison sentences are too long, the official said on condition of anonymity because department rules bar her from giving her name.

Zougam was convicted of placing at least one bomb on a train, and Gnaoui of being a key figure in the plot who served as the right-hand man to its operational chief. The latter, Jamal Ahmidan, killed himself along with six other suspected ringleaders to avoid arrest three weeks after the bombings.

Another of the 10 people who went on hunger strike Sunday is Moroccan Abdelmajid Bouchar, who had also been accused of placing at least one bomb on a train. But, in the end, this did not hold up at trial and he was instead convicted of weapons possession and belonging to a terrorist organization and sentenced to 18 years in jail.

Also on hunger strike are Hassan Haski and Youssef Belhadj, two Moroccans who had been charged with helping mastermind the attacks. They were acquitted of that but convicted of belonging to a terrorist organization and sentenced to 15 and 12 years, respectively.

The other five strikers were also convicted of non-murder charges and sentenced to terms ranging from 12 to 18 years.