Penang Chief Minister Lim Guan Eng has criticised the Home Ministry for its delay in resolving the "invasion" of Lahad Datu, Sabah, by an army linked to the Sulu sultan.
Home Minister Hishammuddin Hussein's latest remark that the invaders are "neither militants nor terrorists" was unacceptable, Lim said.
"If this is so, then why are they in (a village near) Lahad Datu (and) heavily armed?
"If this had happened in Penang, I - as chief minister - would have asked for security assistance from the federal government to drive out or arrest the armed group."
The group allegedly comprises some 100 followers of a sultan in the Philippines, who has claimed that Sabah was "leased" out to the Malaysian government.
Sultan Jamalul Kiram (left) was quoted in an AFP report as saying that his men will remain in Sabah as it is their "home".
Although Malaysian officials have claimed that the group is armed, Jamalul insisted that they are not.
Despite the group's refusal to leave since their arrival on Feb 9, Malaysia has not been firm in its handling of the situation, Lim said.
"If Hishammuddin can't handle the situation immediately and send the armed group out of the country, he should resign," he added.
"The government deported Australian Senator Nick Xenophon, who was unarmed. Here we have an armed group and nothing has been done so far."
Hishammuddin, who is currently in Sabah, has reportedly said that Malaysia is doing everything possible to ensure that stand-off is settled without bloodshed.