New Delhi (CNN) -- India's top court Thursday sentenced a leading Bollywood star, Sanjay Dutt, to five years in prison in connection with bomb attacks in Mumbai in 1993.
The supreme court in New Delhi upheld his conviction on charges of possessing illegal weapons tied to the bombings, which killed 257 people and wounded hundreds more.
He has four weeks to surrender, said his lawyer, Satish Maneshinde.
In 2006, Dutt was convicted of illegally possessing an AK-56 rifle and a 9 mm pistol under India's Arms Act. He was cleared of a more serious accusation of conspiracy in the attacks. Dutt was later sentenced to six years in prison.
He served 18 months in jail before he was granted bail.
"We will await a copy of the judgment of the supreme court. ... Once that is available, we'll advise Sanjay Dutt as to how to go about (this). And it is unfortunate that this has happened," Maneshinde said after Thursday's verdict.
He said his client would abide by the ruling.
"He will have to serve another 3½ years, (which are left after having spent 18 months in jail already)" Maneshinde added.
Dutt's case involves the country's deadliest string of attacks, which were believed to have been carried out by a local underworld in revenge for the demolition of a 16th-century mosque in northern India by Hindu nationalists. The mosque's destruction unleashed a wave of violence that left hundreds dead.
In his defense, the actor has said the weapons were meant to protect his family.
An immensely popular Bollywood celebrity, Dutt is son of a star couple: the late actors Sunil and Nargis Dutt.
His sister, Priya Dutt, is a member of India's parliament.
Sanjay Dutt's biggest hits included the two funny Munnabhai films, in which he played a reformed goon and an advocate of Mahatma Gandhi's principles of nonviolence.
In its ruling Thursday, the supreme court also upheld the death sentence of one of the main convicts in the case. Ten other people on death row had their sentences commuted to life in jail, a defense lawyer, Sriprakash Sinha, told reporters.