For the tally of violations at other Massey sites, the Associated Press checked inspection records for all of the company's approximately 70 underground coal mines in the U.S. from the date of the blast through Thursday. Mines operated by other companies also were inspected during the same period.
Stricklin said the MSHA hasn't been disproportionately targeting Massey since the blast, nor has it increased the pace of inspections.
"We're just going about our regular business," Stricklin said. "I didn't give any instructions to go and look at Massey mines."
Still, Stricklin sharply criticized the company for violations found in the last 10 days.
The violations include conveyer belt problems at Massey's Aracoma Alma No. 1 mine in West Virginia, where a belt fire killed two men in 2006.
"I'm very disappointed," Stricklin said. "You would think that personnnel associated with Massey would be really more careful."
The company's Solid Energy No. 1 mine in Kentucky was cited for allowing coal dust to pile up on three occasions since the explosion.
"That's very troubling," Stricklin said. "Pitiful."
Mines are required to keep methane well below explosive levels with sophisticated ventilation systems and control coal dust by keeping it from piling up and covering it with noncombustible material.
The wrongful death lawsuit filed Thursday by Marlene Griffith in Raleigh County Circuit Court also targets Performance Coal, the Massey subsidiary that operated the underground mine. It's the first such lawsuit against the company over the April 5 blast.
The lawsuit argues that Massey's handling of working conditions at the mine, plus its history of safety violations, amounted to aggravated conduct that rises above the level of ordinary negligence.
Griffith and her husband, William Griffith, were to celebrate their 33rd wedding anniversary at the end of April.
Massey did not immediately respond to requests for comment Friday on the lawsuit or the violations.
The West Virginia Office of Miners' Health, Safety and Training started its own safety sweep of the state's nearly 200 underground mines Friday. Administrator Terry Farley declined to say whether the agency is targeting Massey.
"We don't want 'em to know we're going to be there today," he said.
Inspectors are starting with mines known to produce high volumes of methane and past violations involving rock dusting, ventilation and electrical equipment, Farley said.
Since operators know the state is coming sometime in the next week or two, Farley said he hopes they've addressed significant problems.
Stricklin, of the federal mine safety agency, declined to say whether his agency is planning to increase inspections in the future. District managers across the country have been told to examine ventilation more thoroughly and expedite lab analysis of noncombustible material for controlling coal dust.
MSHA issued the recent citations while conducting spot checks and routine inspections at the Massey operations.
Agency records show the problems were not universal; several Massey mines weren't cited at all after the inspections.
Among those that came up clean is Massey's Tiller No. 1 mine in Virginia. Federal inspectors had warned Massey to improve safety at the mine last fall or face heightened enforcement for a pattern of serious violations.
President Barack Obama has ordered a sweeping review of coal mines with poor safety records and called for stronger mining laws following the Upper Big Branch tragedy.
Mines in West Virginia have been asked to stop producing coal Friday and concentrate on safety in memory of the Upper Big Branch victims.
Separately, Massey said Friday it plans to issue its first-quarter financial results Wednesday afternoon. The explosion occurred in the second quarter.