JERUSALEM — Israel's Supreme Court upheld late Wednesday a controversial law that bans most Palestinians who marry Israelis from living inside the Jewish state.

In a 6-5 ruling, the court agreed that Palestinians who gain Israeli citizenship through marriage pose a security threat. The law is believed to have prevented thousands of Palestinians from living with their spouses.

Parliament passed the law in 2003, at the height of the second Palestinian uprising, a time when militants from the West Bank frequently entered Israel to carry out deadly attacks.

Civil rights groups had argued that Israel's Basic Laws — the country's de facto constitution — grant all citizens the right to family life. They also say that few Palestinian spouses of Israelis have ever been involved in violence.

"Human rights are not a prescription for national suicide," Justice Asher Grunis wrote in the majority opinion.

According to the ruling, about 135,000 Palestinians were granted Israeli citizenship through marriage between 1994 and 2002. Most of them were married to Israeli Arabs. This was a jump from just a few hundred such cases before 1994.

About 20 percent of Israel's citizens are Arabs. They share common roots with the Palestinian community in the West Bank, Gaza and abroad, and frequently intermarry.

The law bans granting citizenship or residency to Palestinian spouses of Israelis, but allows for certain exemptions who are not believed to pose security risks, including Palestinian men older than 35 and women older than 25.

Last year, only 33 out of 3,000 applications for exemptions were approved, said attorney Sawsan Zaher, who filed a challenge to the law on behalf of the Adalah Arab rights advocacy group. She accused the government of interfering in the personal lives of its citizens.

"The court has failed in its main role, which is defending the rights of the minority," Zaher said.