BEIRUT, Lebanon — Turkey and Norway closed their embassies in Syria on Monday and ordered all diplomatic staff withdrawn in response to the government’s harsh repression of the year-old uprising, as opposition activists reported a new spasm of army shelling in Homs, the rebellious city that Syrian security forces had proclaimed purged of insurgents just a few weeks ago.

The developments came as Syrian state media suggested for the first time that parliamentary elections set for May 7 would be delayed, as the government slapped new international travel restrictions on all Syrian men of conscription age, and as a member of a United Nations commission investigating rights abuses in the Syria conflict said she had resigned because of the government’s refusal to allow the panel access inside the country.

Taken together, the news suggested that Syria was heading deeper into mayhem, diplomatic isolation and uncertainty, even as Kofi Annan, the former United Nations secretary general who is trying to halt the hostilities with diplomacy, reported that President Bashar al-Assad’s government had formally responded to his cease-fire plan. No details on Mr. Assad’s response were immediately released.

The decision by Turkey and Norway to close their embassies in Damascus was not unexpected, given the growing number of other countries, including the United States and members of the Arab League, that have taken that step. But Turkey’s decision was considered especially significant because of that country’s 550-mile border with Syria and growing antipathy toward Mr. Assad, whom it once considered a friend.