BEIRUT -- Syrian President Bashar Assad said in a newspaper interview Saturday he won't step down before elections and that the United States has no right to interfere in his country's politics, raising new doubts about a U.S-Russian effort to get Assad and his opponents to negotiate an end to the country's civil war.

In the capital Damascus, a car bomb killed at least three people and wounded five, according to Syrian state TV. It said bomb experts dismantled other explosives in the area.

The Britain-based Syrian Observatory for Human Rights, an activist group, said eight people were killed, including four members of the security forces. Discrepancies in death tolls are common in the chaotic aftermath of bombings in Syria.

Assad's comments to the Argentine newspaper Clarin were the first about his political future since Washington and Moscow agreed earlier this month to try to bring the Syrian regime and the opposition to an international conference for talks about a peaceful resolution to the conflict. The U.S. and Russia have backed opposite sides in the conflict, but appear to have found common ground in the diplomatic push.

The White House and the Kremlin envision holding the meeting next month, but no date has been set. Neither Assad nor the Syrian National Coalition, the main Western-backed coalition group, has made a firm commitment to attend.

In the interview, Assad seemed to play down the importance of such a conference, saying a decision on Syria's future is up to the Syrian people and that the U.S. has no right to interfere. He also said a decision on his political future must be made in elections, and not during such a conference.

"We said from the beginning that any decisions having to do with reform in Syria or any political doing is a local Syrian decision," he said. "Neither the U.S nor any other state is allowed to intervene in it. This issue is dealt with in Syria."

"That's why this possibility is determined by the Syrian people themselves; you go to the elections, you nominate yourself, there's a possibility you win and a possibility you don't," Assad added, hinting he might seek another term.

"This is the possibility. The possibility is not to enter the conference predetermined on something that the people did not determine themselves," he said.

Clarin posted a video of the interview, dubbed into Spanish, on the newspaper's website. The president's Facebook page later posted Arabic subtitles.

The Syrian president's remarks highlight the difficulties the U.S. and Russia face in getting the two sides to agree on the terms of negotiations themselves, let alone brokering a resolution to the civil war itself. The Western-backed Syrian National Coalition has said any transition talks should lead to Assad's ouster.

More than 70,000 people have been killed and several million displaced since the uprising against Assad erupted in March 2011 and escalated into a civil war.

Assad has dismissed those trying to topple him as foreign-backed terrorists. Many in the political opposition say the Syrian president and his inner circle cannot be expected to negotiate in good faith after they brutally suppressed peaceful protests.

In the interview, Assad compared himself to the skipper of a ship riding Syria's turbulent seas, saying "the country is in a crisis and when a ship faces a storm, the captain does not flee."

"The first thing he does is face the storm and guide the ship back to safety," Assad said. "I am not someone who flees from my responsibilities."

Meanwhile, divisions among rebel groups were on display in the country's largest city, Aleppo, where two Islamic militant groups engaged in tit-for--tat kidnappings of each other's fighters.

From the start, Syria's political opposition has been dogged by infighting, while the armed rebel groups have been unable to unite under a unified command.

The tensions in Aleppo involve a coalition of rebel groups known as the Judicial Council and another faction, Ghurabaa al-Sham. The confrontation began earlier this week when the Judicial Council accused the second group of looting factories in an industrial neighbourhood of Aleppo.

The city of 3 million is split between rebel and government control.

Members of the two groups clashed in the area earlier this week, leaving four members of the Judicial Council dead, said Rami Abdul-Rahman, the head of the Observatory.

The Judicial Council then seized dozens of members of the rival group and is still holding them, he said. Ghurabaa al-Sham also took hostages from the Judicial Council, but has since released them, according to Aleppo-based activist Mohammed Saeed.

"The situation is very tense in Aleppo," said Abdul-Rahman, who relies on a network of activists around the country. He said Ghurabaa al-Sham has warned it will bring in some of its fighters from outside the city to take on the Judicial Council if its members are not freed.

Islamic militants fighting in the rebel ranks have become increasingly dominant, often taking up frontline positions. They share the objective of setting up an Islamic state, though some are more nationalistic, while others more religious. One of the most powerful of the Islamic groups, Jabhat al-Nusra, is linked to al Qaeda.

Bilal Saab, a political analyst, said infighting among rival Islamic militant factions is inevitable.

"The scene is so polarized and chaotic, it's ripe for competition and positioning now and after the regime falls," said Saab, director of the Institute for Near East and Gulf Military Analysis, North America.

"The Islamist groups have always been the dominant and most capable, but they have never really been operating under one single umbrella," he added.

In another sign of the chaos bred by the civil war, gunmen abducted the elderly father of Syria's deputy foreign minister, Faisal Mekdad, his office said. Mekdad's father, who is in his 80s, was seized Saturday in the village of Ghossom in the southern Daraa province, Mekdad's office said.

The Observatory said regime forces arrested relatives of an alleged suspect in the kidnapping.