German Interior Minister Otto Schily said he would travel to London in the aftermath of the deadly series of blasts there Thursday and urged increased vigilance at home. Schily said he had spoken with British Home Secretary Charles Clarke earlier and now worried there would be a "high number of fatalities" from the attacks. He said he would go to the British capital Friday to gain a better understanding of the situation. Authorities in London said the wave of explosions had killed at least 33 people and injured more than 340. Schily compared the London assault to other catastrophes in recent years. "This was a treacherous criminal attack along the lines of those in New York, Madrid, Istanbul and other places on earth," he said. He said that Germany had boosted security at the borders, at airports and one the nation's train lines and in front of key embassies. The Berlin public transportation authorities said earlier they had stepped up patrols on metro and bus lines. Schily pressed Germans to be alert to suspicious activity but said there was no indication of an increased threat to German interests. He said he did not yet know if there had been Germans among the London victims.