ABU DHABI—Syria's government on Tuesday said it was continuing military operations in three areas across the country, as rights activists said those sieges and continued mass arrests threaten to cripple Syria's seven-week uprising.

Syrian state television said army units and troops were continuing to fight "armed terrorist groups" in the suburbs of Deraa in the south, Banias on the western coast and in the central city of Homs. The government has maintained that Syria has been subject to a foreign...