BEIRUT, Lebanon — Most of Syria’s rebel groups refused to come to the Russian-sponsored peace conference in the resort town of Sochi on Tuesday. Those who did come refused to leave the airport.

Some delegates said there was no point in drafting proposals because the talks’ final statement was largely agreed upon before they began. Instead, some brought empty suitcases to fill with Russian goods to sell back home, and the schedule was almost evenly split between talks and meals.

It might have been a political comedy, except that back in Syria, at least 35 people were reported killed since Sunday, including a mother and three children, in the government’s Russian-backed aerial bombing campaign on rebel-held territory. The week before, eight people were killed, including a small child, when a rebel mortar round hit Damascus’s old city.

The Sochi talks were called by Russia’s president, Vladimir V. Putin, with the stated goal of breaking a longstanding impasse in negotiations to end the seven-year civil war. Those other talks, sponsored by the United Nations, have made no progress toward the negotiated political transition they envision.