Four suspected Daesh-linked terrorists were arrested by the security forces in central Visayas and southern Mindanao islands Sunday.
The authorities said the operations were to arrest hundreds of members of the Maute group, Abu Sayyaf and Bangsamoro Freedom Fighters for inciting acts of rebellion.
Capt. Leopoldo Panopio, commander of the Philippine Coast Guard in Northern Mindanao, said a sister of the Maute leaders -- Omarkhayam and Abdullah -- and two others had been arrested near Iloilo port in Visayas on Sunday.
In comments reported by GMA news, he said the sister of Maute leaders was arrested at 3 p.m. local time (0700GMT) Sunday while on board a ship, the MV St. Therese of the Child Jesus.
According to Panopio, the woman admitted she was the wanted sister and that she used fake identities at the Cagayan de Oro City port.
Omarkhayam and Abdullah are the known leaders of the Daesh-inspired Maute group, which led the siege in Marawi City of Mindanao island.
The number of people killed in the ongoing firefight between government troops and Daesh-linked terrorists in the city has risen to 310, a military official said on Friday.
Lt. Col. Emmanuel Garcia, commander of the Armed Forces' 4th Civil Relations Group, said 225 Maute armed group members, 59 security personnel and 26 civilians have been killed since the outbreak of hostilities on May 23.
The conflict prompted President Rodrigo Duterte to place Mindanao under martial law, which is now in its fourth week.