PHNOM PENH, Dec. 15 (Xinhua) -- Thai military forces' attack on Cambodia in the 4th Military Region has entered further deep into Cambodian sovereign territory, said the Cambodian Ministry of Defense on Monday.

The Thai military forces have expanded their airstrikes to a location in northwest Cambodia's Siem Reap province, the ministry said in a press release, adding that the Thai military used an F-16 fighter jet to drop two bombs near a displaced civilian camp in the province at 10:00 a.m. on Monday local time.

The fresh border conflict with Thailand has left 12 Cambodian civilians dead and 74 others injured as of 6 p.m. local time on Sunday, Cambodia's Interior Ministry Spokesperson Touch Sokhak said at a press briefing on Monday.

Meanwhile, the number of displaced persons in Cambodia has exceeded 403,000, including approximately 208,000 women and about 96,000 children, according to the spokesperson.

Cambodian Defense Ministry's Undersecretary of State and Spokesperson Lt. Gen. Maly Socheata said that from Sunday midnight until Monday morning, the Thai military forces continued to fire artillery shells at multiple locations in Cambodian territory.

The Cambodia-Thailand border conflict has reignited since Dec. 7, and both sides have accused the other of initiating the attack. Enditem