* Last Communist leader Jaruzelski buried in Warsaw
* In act of reconciliation, Walesa offers condolences to family
* Protesters gatecrash burial ceremony
* Many Poles see Jaruzelski as Moscow-backed dictator (Updates with burial ceremony)
By Jakub Iglewski and Christian Lowe
WARSAW, May 30 (Reuters) - Lech Walesa, head of the Solidarity movement that ended Communism in Poland, knelt in prayer on Friday at a Catholic funeral mass for General Wojciech Jaruzelski, the Communist leader who for decades was his sworn enemy.
But not all Poles are ready to reconcile with Jaruzelski, who oversaw violent crackdowns on pro-democracy activists before the Iron Curtain fell in 1989. Protesters gatecrashed his burial ceremony, shouting "traitor!" and "Go back to Moscow!"
Jaruzelski died on Sunday aged 90 in a military hospital. He declared martial law in 1981 to put down an uprising by Walesa's movement, and his subordinates killed dozens of people.
Though his critics called him a Kremlin stooge, he played a role ushering in democracy in Poland: he allowed partially-free elections to take place and when they were won by his anti-Communist opponents, he stepped aside without bloodshed.
Even some of his most bitter opponents acknowledge he may have been a Polish patriot who cracked down on dissent because, if he had not, his Soviet masters would have sent in tanks, finally crushing any hopes of Polish independence.
Walesa, 70, dressed in a black suit and black tie, sat in the front pew of the Cathedral of the Polish Army, alongside serving president Bronislaw Komorowski and former head of state Aleksander Kwasniewski.
When Bishop Jozef Guzdek, who was celebrating the mass, asked worshippers to offer each other the sign of peace, Walesa crossed the aisle and shook the hands, in turn, of Jaruzelski's widow, Barbara, his daughter Monika and his school-age grandson.
Jaruzelski was an atheist but a clergyman at the cathedral said that, 13 days before his death, he had asked a Catholic priest to administer the last rites.
Komorowski, in an address from the pulpit, said it was now up to God, and not other people, to judge Jaruzelski.
He described him as, "a politician, a soldier, a man carrying the burden of responsibility for the most difficult and perhaps most dramatic decisions in Poland's post-war history."
After the mass, Jaruzelski was buried at the Powazki military cemetery, near the centre of the Polish capital.
A military band played and soldiers with rifles fired a salute as a small black chest containing Jaruzelski's cremated remains was handed to a cemetery worker in blue overalls who placed it in a hole in the ground. Jaruzelski's widow sobbed, and her daughter put her arm around her.
A short distance away, a large crowd shouted anti-Communist slogans and blew whistles. At one point, a small group of the protesters pushed their way into the corner of the cemetery where Jaruzelski was being buried and shouted "disgrace."
One protester, Danuta Regulska, said she was the sister of Sylwester Zych, a priest and anti-Communist activist who died in unexplained circumstances in 1989.
Regulska said she believed he was killed on the orders of the Communist authorities. "They wouldn't even bury my brother properly. And now my army, the Polish army, accords honours to this man," she said, referring to Jaruzelski. "It's a disgrace."
Though it was a state funeral in accordance with Jaruzelski's status as a former president, President Komorowski stayed away from the burial ceremony, as did Walesa, the prime minister, and most of the government. (Writing by Christian Lowe; Editing by Stephen Addison)