The leader of a Muslim insurgent group in southern Thailand denounced the recent announcement of a cease-fire in the region as a hoax, while suspected rebels set off a bomb Monday that wounded seven people.

Six policemen and a civilian were wounded when the homemade bomb triggered by a cell phone exploded along a road in Yala province, police Lt. Chaiya Phoorahong said. He said Muslim rebels were suspected in the attack.

More than 3,300 people have been killed in drive-by shootings and bombings since early 2004, when a decades-old insurgency flared in Thailand’s three southernmost provinces, the only Muslim-majority areas in the predominantly Buddhist country.

Shortly before Monday’s violence, the deputy president of the Pattani United Liberation Organization, or PULO, denounced an alleged cease-fire agreement between the Thai government and a group called the United Southern Underground, and said the “struggle for independence” would continue.

The previously unknown group, claiming to represent others involved in the insurgency, announced last Thursday that it had ended all violence in the region. The announcement was greeted with widespread doubt.

“It is an opportunist group which was created and orchestrated by an individual to confuse and divide the liberation movement,” the PULO’s Lukman B. Lima said in an e-mail to The Associated Press.

He said the announcement was a political gimmick by a former military commander.

Former army commander and Defense Minister Chetta Thanajaro, who now heads a small political party, has said the agreement was the result of informal talks he held with leaders of the insurgency.

He said the organization that made the announcement represented 11 different underground groups operating in southern Thailand, but did not identify them or their leaders.

Prime Minister Samak Sundaravej earlier said his government was not holding talks with any separatists, but that at least two insurgent groups were in discussions with mediators in Geneva.

The military and scholars studying the insurgency say it has been carried out by a loose, secretive alliance of various groups. Their common goal is believed to be independence or autonomy for the region, though no comprehensive statement of their aims has been made public.

PULO is one of the oldest of the insurgent groups but is not believed to be the current driving force behind the violence. Most of its leaders, including Lukman, are in exile in Sweden and elsewhere.

Thailand annexed the independent sultanate of Pattani in the early 20th century. Residents of the former sultanate, now mostly Thailand’s three southernmost provinces, have long complained of being treated as second-class citizens, with poor educational and job opportunities.

The government has emphasized the use of military force to quash the insurgency, but has had little success in ending the violence.