Story highlights

NEW: Twenty others were wounded, the interior minister says

NEW: He warns Gadhafi loyalists that they are "playing with death"

Bani Walid was a holdout of pro-Gadhafi forces

Tensions have continued since the city's fall last year

CNN  — 

Five people were killed and 20 wounded when clashes broke out between pro- and anti- Gadhafi forces in the Libyan city of Bani Walid, one of the last strongholds of those loyal to the late leader, a government official said Monday.

Libyan Interior Minister Fawzi Abdul Aal warned that National Transitional Council forces would not tolerate fighters loyal to Moammar Gadhafi.

“I want to send a message to all people who belong to the former regime: You’re playing with death,” the minister said on state television, vowing to reassert control.

“We will not be merciful with them. The security of Libya is the highest priority,” he added.

Earlier in the day, ministry spokesman Abdelmonem al-Tunsi said Gadhafi fighters were still in control of some entrances to the city.

Bani Walid was a holdout of pro-Gadhafi loyalists until the very end of the fighting late last year, and tension between residents and NTC fighters continued after the city’s fall.

Elsewhere in the country, residents in Tripoli said checkpoints have been set up in and around the capital as fighters are on high alert.

CNN’s Jomana Karadsheh, Yousuf Basil and Rajah Razek contributed to this report.