Malaysian soldiers launched an attack on Tuesday against an armed clan in the Philippines, part of a continued effort to end a three-week long standoff in Sabah after violence in recent days that already killed at least 27 people, a Malaysian government official said.
The operation to take over an area occupied by about 180 Filipinos, dozens of them armed, began early Tuesday, a spokesman for Malaysian prime minister Najib Razak said.
The government sent seven army battalions to the area on Monday to reinforce police, Al Jazeera's Florence Looi reported, adding that an "all-out assault" could follow. No casualties have been reported in Tuesday's attack.
Ismail Omar, Malaysian police inspector-general, said in a press conference that the ongoing military operation is centred in the area of Kampung Tanduo, which has been "sealed off" within 4km radius.
A firefight first broke out on Saturday, when the Malaysian police tried to force the group to surrender, initially killing at least 10 people. The armed group launched a counter-attack killing at six Malaysian police, but also losing an additional seven of its members, raising concerns the violence was spreading.
"After the first attack, I have asserted that the intruders must surrender and if they refuse the authorities of this country will take action," Najib said in a statement.
The ongoing violence has already displaced many native Filipinos living in Sabah. There are an estimated 800,000 Filipinos living there.
On Sunday evening, about 300 Filipinos have arrived in Zamboanga in southern Philippines after being "deported" from Sabah, Al Jazeera's Jamela Alindogan reported.
"A crackdown on Filipinos are expected to intensify in the coming weeks," Alindogan said.
Earlier, Philippine president Benigno Aquino had called on members of the Sabah clan to surrender, saying negotiations can only proceed if they lay down their arms.
Centuries-old territorial claim
Members of a Muslim royal clan, who call themselves the Royal Sulu Army and hail from the southern Philippines, landed in a coastal village in Sabah on February 9 to claim the territory as their own, citing ownership documents from the late 1800s.
They are also demanding an increased payment from Malaysia for their claim as the rightful owners of Sabah.
The Malaysian government continues to pay the Kiram clan of Sulu a supposed annual rent of $1,500 for the use of more than 73,000 square kilometres of land in Sabah.
Malaysia has refused their demands and, along with the Philippine government, has urged the group to return home.
The violence has sparked a political crisis ahead of elections for both the Philippine and Malaysian governments and raised concerns of instability in resource-rich Sabah state.
The crisis also comes a crucial stage of peace negotiations arranged by Malaysia between the Philippine government and the Moro Islamic Liberation Front, the largest Muslim rebel group in the southern Philippines.
The group has ignored appeals from Aquino to leave Sabah or face prosecution at home on charges of triggering armed conflict.