On January 13, 1951, Giáp moved the 308th and 312th Divisions, made up of over 20,000 men, to attack Vĩnh Yên, 20 miles (32 km) northwest of Hanoi, which was manned by the 6,000-strong 9th Foreign Legion Brigade.
On March 23, Giáp tried again, launching an attack against Mạo Khê, 20 miles (32 km) north of Haiphong. The 316th Division, composed of 11,000 men, with the partly rebuilt 308th and 312th Divisions in reserve, went forward and were beaten in bitter hand-to-hand fighting against French troops. Giap withdrew, having lost around 500 troops (by Việt Minh estimation) to over 3,000 (by French estimation) dead and wounded by March 28.
Giáp launched yet another attack, the Battle of the Day River, on May 29 with the 304th Division at Phủ Lý, the 308th Division at Ninh Bình, and the main attack delivered by the 320th Division at Phat Diem south of Hanoi.
On July 31, French General Charles Chanson was assassinated during a propaganda suicide attack at Sa Đéc in South Vietnam that was blamed on the Việt Minh although it was argued in some quarters that Cao Đài nationalist Trình Minh Thế could have been involved in its planning.