Three Abu Sayyaf members and a soldier were killed in a firefight in Patikul, Sulu Saturday morning, the military said.

Fifteen soldiers were also injured in the hour-long firefight against Abu Sayyaf bandits under the leadership of Almujer Yaddah at Sitio Darayanat at the boundary of Barangays Danag and Buhanginan in Patikul town.

The wounded soldiers were brought to a hospital in Jolo, Sulu for medical treatment. The body of the dead soldier was brought to the military mortuary at the Joint Task Force Sulu headquarters.

During clearing operations, troops recovered the body of a still unidentified Abu Sayyaf member.

"Our operating troops were also able to see the bandits dragging two bodies of their companions who appeared to be already lifeless," Joint Task Force Sulu commander Brigadier General Cirilito Sobejana said in a statement.

The military pursued offensives against the Abu Sayyaf after receiving reports that the bandits were keeping hostages in the area.

"The soldiers are very careful in their movements since it is believed that the Abu Sayyaf group is still carrying with them around six to seven kidnap victims," Sobejana said.

Meanwhile, state forces on Thursday rescued two fishermen held hostage by the Abu Sayyaf group for seven months.

The hostages, identified as Reyjim Rocabo, 41, and Roel Leones, 37, were on-board a motorcycle when they were intercepted by state forces in Daang Puti, Patikul town.

The two were known to have been held by Yaddah's group. It was unclear how they ended up where they were found.

"Rocabo and Leones are now under the custody of the Anti-Kidnapping Group and will eventually be turned-over to their families after actionable information [is] taken from them," said Sobejana.

The hostages were snatched by armed men while fishing in the Celebes Sea off Sulu last December.

One of their fellow crew members, Roy Ramos, was rescued in June, while their boat captain, Noel Esconde, was beheaded by the Abu Sayyaf in April.

Earlier this week, the bodies of two beheaded Vietnamese nationals were found in Basilan. They were among six Vietnamese crewmen seized by the Abu Sayyaf off their cargo ship in November.

• Read: Bodies of 2 beheaded Vietnamese found in Basilan

As of this posting, the military said the Abu Sayyaf, notorious for its kidnap-for-ransom operations, could be holding 20 more hostages, of which 16 are foreigners and four are Filipinos.