Represenatives of the Colombia government and the M-19 guerrillas holding an estimated 35 persons hostage in the embassy of the Dominican Republic held a second round of talks today as the siege entered its eighth day.

Two Foreign Ministry officials, Camiko Jiminez and Villalba and Ramiro Zambrano, who represented the government during the first round of talks Sunday, met again with a woman guerrilla, her head covered by a white hood, in a van parked in front of the embassy building.

The guerrilla was accompanied by Richardo Galan, Mexico's ambassador to Colombia, one of 13 ambassadors held inside the embassy since last Wednesday. Among those being held is U.S. Ambassador Diego Asencio.

No government communique was issued after today's talks, which lasted for more than two hours. At one point, the guerrilla and Galan left the truck and returned to the embassy, apparently for further instructions. They then returned to talk with the two Foreign Ministry officials for another hour before the discussions ended.

Most political and diplomatic observers believe that the situation will not be resolved before elections for municpal councils and departmental legislatures on Sunday.

An afternoon newspaper here reported it had learned from government sources that Villalba and Zambrano today told the guerrillas that the government would not meet their principal demands -- the release of 311 prisoners and $50 million in ransom.

The newspaper also said the government had offered the guerrillas safe passage out of Colombia in exchange for ending the siege and the safe release of the hostages. Although it has been known for several days that the government is determined not to release prisoners in exchange for the hostages, it was impossible today to confirm the newspaper's account.

One diplomat said that the government "is virtually hermetically sealed," and added that it has not made its negotiating position completely known, even to the embassies whose ambassadors are being held.

During the first five days of the siege, journalists were able to call the embassy and sometimes learned details from the guerrillas or from ambassadors who would either answer or come to the phone. But the telephone numbers were changed Sunday making incoming calls from journalists impossible.

The U.S. Embassy confirmed that Ambassador Asencio has been allowed to continue his daily calls to American officials here. The ambassador called the embassy again today.

There were reports that the guerrillas had agreed to release at least several more of the hostages after today's talks, as happened after Sunday's discussions. But by late afternoon no additional hostages had been released.

There has been much confusion about the number of hostages still in the embassy.

Those countries whose ambassadors are known to be in the embassy include: the Dominican Republic, the United States, Brazil, Venezuela, Haiti, Austria, Switzerland, Uruguay, Egypt, Israel, Guatemala, Mexico and the papal nuncio.