Caracas, Venezuela ? Heavily armed navy troops seized two oil tankers from strikers Wednesday as deeply divided Venezuelans took to the streets — both to protest and to search for cash and food as a strike aimed at ousting President Hugo Chavez expands.

Internationally mediated negotiations between Chavez’s government and his opponents, which have produced few results, got a boost with a new proposal for a constitutional amendment that would allow elections early next year. Some lawmakers on both sides indicated the deal might work.

After four days without an oil tanker leaving Venezuela because of the strike, Chavez said his government was close to getting the flow of oil going again. He said that an oil tanker was being loaded Wednesday. Long lines at gas stations disappeared, indicating domestic distribution networks were returning to normal.

“We are overcoming the crisis,” Chavez said. “The situation is progressively improving. The supply of gasoline is flowing.”

Chief mediator Cesar Gaviria, secretary-general of the Organization of American States, said there was hope for an agreement. But he warned that a deal must come soon “or we will find increasing demands by the opposition and that may take Venezuela to a confrontation with a high risk of violence.”

Most of the fleet of Venezuela’s oil industry — the world’s fifth-largest and a key source of U.S. fuel — is anchored to protest Chavez’s 4-year-old rule, which opponents say has made millions poorer and driven the country toward communism.

The two tankers seized early Wednesday — one filled with gasoline, the other with natural gas — were the most visible symbols of a 10-day-old general strike that has crippled this South American nation.

Navy troops climbed ropes alongside the tankers Pilin Leon and Yavire, held their crews at gunpoint and arrested the captains. They brought new captains for both vessels, but it was unclear whether the crews would obey them.

“Two of (the navy troops) were carrying machine guns — inside a tanker carrying natural gas,” Yavire machine chief Cesar Franco told Union Radio. “We were afraid they’d get a shot off.”

Lawyer Gonzalo Himiob, who represents the captains of the seized tankers, called the navy action “piracy and confiscation” and said the crews would refuse to work under new captains.

Captains on two other anchored tankers said navy officers were on board and were trying to persuade them to deliver their cargoes. Capt. Roberto Sanchez, aboard the Insiarte, told The AP that the talks were “cordial.”

In Vienna, the secretary-general of the Organization of Petroleum Exporting Countries, Venezuelan Alvaro Silva, warned that the crisis was “worrying and is affecting the market in general.” The International Energy Agency estimated Venezuela’s oil production has fallen from up to 3 million barrels a day to only 1 million.

Raucous demonstrations continued on the streets by both foes and followers of the president.

The opposition, which launched the strike to demand a nonbinding referendum on Chavez’s rule, now wants general elections soon — which Chavez has said the constitution prohibits.

“We want Chavez to fall, nothing less,” said 71-year-old opposition protester Selina Palaver.

With food and cash becoming scarce, thousands of people packed a government-organized street market offering cut-rate prices along several blocks of a main boulevard Wednesday. A band tried to rally Christmas spirit with music traditionally played during the holidays.

Lines several blocks long formed in front of banks, which were open only three hours.

The State Department advised Americans to put off all travel to Venezuela and U.S. citizens already there to consider leaving.