BEIRUT — Syria derided U.N. chief Ban Ki-moon as biased and called his comments “outrageous” Saturday after he blamed the regime for widespread cease-fire violations — the latest sign of trouble for an international peace plan many expect to fail.

In new fighting Saturday, activists said regime forces battled army defectors near President Bashar Assad’s summer palace in a coastal village and shelled a Damascus suburb in pursuit of gunmen. State media said government troops foiled an attempt by armed men in rubber boats to land on Syria’s coast, the first reported attempt by rebels to infiltrate from the sea.

The regime’s verbal attack on the U.N. secretary general raised new concerns that Assad is playing for time to avoid compliance with a plan that could eventually force him out of office. Under special envoy Kofi Annan’s six-point road map, a cease-fire is to be followed by the deployment of as many as 300 U.N. truce monitors and talks between Assad and the opposition on Syria’s political future.

But Annan’s April 12 cease-fire deadline was widely ignored. The regime continued to attack opposition strongholds, while rebel fighters kept targeting security forces with roadside bombs and shooting ambushes. Defying a major truce provision, the Syrian military failed to withdraw tanks and soldiers from the streets.

Ban and Annan have cited violations by both sides, but generally portrayed the regime as the main aggressor. On Friday, Ban said Syria’s repression of civilians had reached an “intolerable stage” and demanded that the regime “live up to its promises to the world.” His comments came just hours after a suicide bombing the regime blamed on anti-government “terrorists” killed 10 people in Damascus.

An editorial Saturday in the state-run Tishrin newspaper said Ban has avoided discussing rebel violence in favor of “outrageous” statements against the Syrian government. The editorial said that the international community has applied a double standard, ignoring “crimes and terrorist acts” against Syria and thus encouraging more violence.

Mass protests against Assad erupted in March 2011, but gradually turned into an insurgency in response to a violent regime crackdown. Assad’s regime denies it faces a popular uprising, claiming it is being targeted by a foreign-led terrorist conspiracy.

Saturday’s comments were the regime’s harshest against the U.N. since Syria announced last month it would abide by the Annan plan. The Syrian opposition and its Western backers argue Assad is not sincere and just buying time to consolidate his hold on Syria.

The regime “wants to make the U.N. a party to the conflict, rather than a mediator, and to stretch out the process to prevent any kind of serious change,” Rami Khoury, an analyst at the American University of Beirut, said of Saturday’s editorial.

However, the regime and its supporters argue that the world intentionally ignores rebel cease-fire violations, such as targeted killings of security officials, said Peter Harling of the International Crisis Group think tank who has traveled in Syria.

“In the regime’s narrative, its use of force is only a reaction to such assaults,” he said. “Officials and sympathizers cling to the idea that they are fighting a legitimate struggle against a fifth column of extremists.”

Russia, Syria’s main ally, repeatedly has demanded that more attention be paid to rebel violations of the Annan plan.

In fighting Saturday, government troops exchanged fire with about 30 soldiers after they defected at a military base near the coastal village of Burj Islam, according to Syria-based activist Mustafa Osso and the Britain-based Syrian Observatory for Human Rights, an activist group.