NAIROBI, Kenya — As rebels in Chad fought for a second day to take control of the nation’s capital, analysts said Sunday that the outcome of the attempted coup could have far-reaching implications for the Darfur conflict in neighboring Sudan.

Tanks rolled through N’Djamena, Chad’s capital, on Sunday, turning the streets into a battle zone between the government and rebels littered with bodies. Fighting also raged in an area where about 420,000 refugees live near the border with Sudan’s Darfur region.

President Idriss Deby appeared to be holed up with a large force of loyal troops in his presidential palace.

The aid group Doctors Without Borders reported that scores of civilians had been wounded, mostly from errant gunfire. Looting has been reported in N’Djamena, and the French government evacuated at least 500 foreigners.

Rebels claimed to have seized control of the town of Adre, along the eastern border with Sudan, while Chadian authorities told reporters that the attackers had included Sudanese troops and had been repelled. Neither report could not be verified.

A collapse of Deby’s regime likely would be felt beyond Chad’s borders. Deby has supported Darfur rebels in western Sudan, and his fall would threaten to tilt the balance of power in Darfur toward the Sudanese government.

Chad and its former colonizer, France, accused Sudan of masterminding the coup attempt in Chad ahead of the arrival of the EU force, which is to operate along the volatile border with Darfur.

Sudan has repeatedly denied any involvement in the fighting. But Chadian Gen. Mahamat Ali Abdallah Nassour alleged that Sudanese troops were involved and called it a “declaration of war” from Sudan.

“This could be a big win for Sudan,” said Reed Brody, special counsel for Human Rights Watch, the international advocacy group. “The rebel alliance will be beholden to Khartoum. They will control one of the main access points and windows into Darfur.”

Chad is currently host to about 250,000 Darfur refugees who fled violence in western Sudan over the past four years. Chad also serves as an important gateway for humanitarian groups, journalists, human-rights activists and peacekeepers, many of whom are unable to access Darfur through other areas of Sudan. Experts said that access could be at risk if a Sudan-friendly regime suddenly took control of Chad.

In addition, Darfur rebel groups use Chad as a safe haven and launching point for attacks against Sudanese government troops. Deby, who seized control of Chad through a coup in 1990, is from the same tribe as one of the main Darfur rebel movements. His government has supplied Darfur rebels with guns and allowed them to set up training camps along his border.