JAKARTA (AFP) - A suicide bomber wounded at least 26 people when he struck a prayer room in an Indonesian police compound in the first suicide attack on a mosque in the country, police said. The bomber began the Friday prayers along with other worshippers, and was killed immediately in the explosion at around 12:15 pm (0515 GMT) at police headquarters in the city of Cirebon, West Java province, they said. The blast appeared to mark a return of major terror attacks to Indonesia after almost two years, and followed a series of arrests of suspected extremists. "The blast occurred at the beginning of the Juma prayer," Indonesian police spokesman Anton Bachrul Alam said. "The man was praying in the third row. Suddenly there was a blast," an eyewitness named Anton was quoted as saying by Detik news website. The explosion injured several local police officers, including the Cirebon police chief, who were praying around the attacker. Police said they were still trying to identify the bomber - who was wearing dark clothing and was thought to be in his late 20s - and his motives. It was the first time a suicide bomber had targeted people inside a mosque in Indonesia, the world's most populous Muslim-majority country, Narapatih Centre terror analyst Mardigu Prasantyo said. "This never happened before in Indonesia. It's outrageous," Prasantyo said. "This is much more dangerous than previous attacks in the country, as we had never thought a mosque would be a target," he said. "Targeting a mosque ... happened in Istiqlal mosque in 1999 and also in Yogyakarta's mosque in 2000, although the blast failed to happen," said head of Indonesia's National Counter-Terrorism Agency, Ansyaad Mbai. The Istiqlal blast hit the mosque's basement, injuring three, but neither was a suicide attack. Prasantyo said the bomber might be linked with a group that recently distributed low-explosive packages in the Jakarta area. Last month, bombs hidden in a hollowed-out books were sent to several addresses including those of liberal Muslim figures and a counter-terrorism official, but no one was killed. The head of rights group the Setara Institute, Hendardi, said they "condemn this act of terrorism, which is a cowardly act". The country of 240 million has been rocked by a series of bombings staged by regional terror network Jemaah Islamiyah in recent years, including the 2002 Bali bombings which killed 202 people, including 88 Australian tourists.